Update installation guide to be compliant with Qubes OS 4.1.2

Installation guide has been updated so it reflects the process of
installing Qubes OS 4.1.2 as well as some minor improvements, like
mentioning the importance of glossary.

Author: aronowski

user/downloading-installing-upgrading/installation-guide.md

@@ -23,6 +23,8 @@ title: Installation guide
 
 Welcome to the Qubes OS installation guide! This guide will walk you through the process of installing Qubes. Please read it carefully and thoroughly, as it contains important information for ensuring that your Qubes OS installation is functional and secure.
 
+This guide assumes you're familiar with the [glossary](/doc/Glossary/). Make sure to read it first before moving on.
+
 ## Pre-installation
 
 ### Hardware requirements
@@ -222,18 +224,18 @@ As soon as you press **Done**, the installer will ask you to enter a passphrase
 
 [![Select storage passhprase](/attachment/doc/select-storage-passphrase.png)](/attachment/doc/select-storage-passphrase.png)
 
-When you're ready, press **Begin Installation**.
-
-[![Installation summary ready](/attachment/doc/installation-summary-ready.png)](/attachment/doc/installation-summary-ready.png)
-
 ### Create your user account
 
-While the installation process is running, you can create your user account. This is what you'll use to log in after disk decryption and when unlocking the screen locker. This is a purely local, offline account in dom0. By design, Qubes OS is a single-user operating system, so this is just for you.
+Create your user account. This is what you'll use to log in after disk decryption and when unlocking the screen locker. This is a purely local, offline account in dom0. By design, Qubes OS is a single-user operating system, so this is just for you.
 
 Select **User Creation** to define a new user with administrator privileges and a password. Just as for the disk encryption, this password should be complex. The root account is deactivated and should remain as such.
 
 [![Account name and password](/attachment/doc/account-name-and-password.png)](/attachment/doc/account-name-and-password.png)
 
+When you're ready, press **Begin Installation**.
+
+[![Installation summary ready](/attachment/doc/installation-summary-ready.png)](/attachment/doc/installation-summary-ready.png)
+
 When the installation is complete, press **Reboot**. Don't forget to remove the installation medium, or else you may end up seeing the installer boot screen again.
 
 ## Post-installation
@@ -260,15 +262,29 @@ By default, the installer will create a number of qubes (depending on the option
 
 Let's briefly go over the options:
 
-* **Create default system qubes:** These are the core components of the system, required for things like internet access.
-* **Create default application qubes:** These are how you compartmentalize your digital life. There's nothing special about the ones the installer creates. They're just suggestions that apply to most people. If you decide you don't want them, you can always delete them later, and you can always create your own.
-* **Create Whonix Gateway and Workstation qubes:** If you want to use Whonix, you should select this option.
-  * **Enabling system and template updates over the Tor anonymity network using Whonix:** If you select this option, then whenever you install or update software in dom0 or a template, the internet traffic will go through Tor.
-* **Create USB qube holding all USB controllers:** Just like the network qube for the network stack, the USB qube isolates the USB controllers.
-  * **Use sys-net qube for both networking and USB devices:** You should select this option if you rely on a USB device for network access, such as a USB modem or a USB Wi-Fi adapter.
-* **Do not configure anything:** This is for very advanced users only. If you select this option, you'll have to set everything up manually afterward.
+#### Templates Configuration
+
+This section provides the [templates](/doc/template/) you wish to install and which one to use as the default one. The default template settings can always be changed after this initial configuration too.
+
+#### Main Configuration
+
+* **Create default system qubes (sys-net, sys-firewall, default DispVM):** These are the core components of the system, required for things like internet access.
+  * **Make sys-firewall and sys-usb disposable:** The qubes responsible for firewalling/isolating network traffic and *holding* certain hardware devices like USBs, Bluetooth adapter, integrated cameras, etc. (*sys-usb* only, if applicable) will be made disposable. Enabled by default as generally there seem to be no benefits for them being persistent anyhow.
+  * **Make sys-net disposable:** The qube handling your network devices will be made disposable. This will result in loss of remembered Wi-Fi passwords and therefore automatic Wi-Fi connections each time the qube gets booted. Disabled by default for a more user-friendly experience but if you don't mind storing the aforementioned passwords e.g. in an offline database, you may turn it on for privacy enhancements (no broadcasting of saved Wi-Fi network names).
+* **Create default application qubes (personal, work, untrusted, vault):** These are how you compartmentalize your digital life. There's nothing special about the ones the installer creates. They're just suggestions that apply to most people. If you decide you don't want them, you can always delete them later, and you can always create your own.
+* **Use a qube to hold all USB controllers (create a new qube called sys-usb by default):** A dedicated qube that *holds* certain hardware devices like USBs, Bluetooth adapter, integrated cameras, etc. (*sys-usb*) will be created.
+  * **Use sys-net qube for both networking and USB devices:** certain hardware devices will be *held* by *sys-net* instead. May make experience with USB Wi-Fi adapters more user-friendly and seamless.
+  * **Automatically accept USB mice (discouraged):** If enabled, upon the connecting of a device that presents itself as a USB mouse, it will be automatically forwarded to dom0. Disabled by default so once such device is connected, manual user interaction is required to confirm forwarding that device. This results in additional security benefits - e.g. a malicious device presenting itself as a mouse will be rendered useless until a confirmation dialog in dom0 is accepted.
+  * **Automatically accept USB keyboard (discouraged if non-USB keyboard is available):** See the point above about USB mice. The same applies here. Enabling this is mostly beneficial to modern stationary workstations where only a USB keyboard can be used for typing. If you can use a PS/2 keyboard (generally laptops use an emulated PS/2 for their internal keyboards), you may want to leave this option disabled for additional security.
+* **Create Whonix Gateway and Workstation qubes (sys-whonix, anon-whonix):** If you want to use Whonix, you should select this option.
+  * **Enable system and template updates over the Tor anonymity network using Whonix:** If you select this option, then whenever you install or update software in dom0 or a template, the internet traffic will go through Tor.
+
+#### Advanced Configuration
+
+* **Use custom storage pool:** Here you can specify custom names for the LVM pool holding your qubes' filesystems as well as LVM Volume Group name. Unless you're preparing a customized environment on your machine (e.g. dual booting distinct Qubes OS releases), you can leave this option unchecked.
+* **Do not configure anything (for advanced users):** This is for very advanced users only. If you select this option, you'll have to set everything up manually afterward.
 
-When you're satisfied with you choices, press **Done**. This configuration process may take a while, depending on the speed and compatibility of your system.
+When you're satisfied with you choices, press **Done**. This configuration process may take a while, depending on the speed of your computer and the selected options described above (the more templates to be installed, the longer the configuration process will take).
 
 After the configuration is done, you will be greeted by the login screen. Enter your password and log in.