Very short description of exit codes and how to access them (#3112)

Author: Rowlando13

docs/command-line-reference.md

@@ -0,0 +1,48 @@
+# General Command Line Topics
+
+```{currentmodule} click
+```
+
+```{contents}
+---
+depth: 1
+local: true
+---
+```
+
+## Exit Codes
+
+When a command is executed from the command line, then an exit code is return. The exit code, also called exit status or exit status code, is a positive integer that tells you whether the command executed with or without errors.
+
+| Exit Code | Meaning                                         |
+|-----------|-------------------------------------------------|
+| 0         | Success — the command completed without errors. |
+| > 0       | Executed with errors                            |
+
+Exit codes greater than zero mean are specific to the Operating System, Shell, and/or command.
+
+To access the exit code, execute the command, then do the following depending:
+
+```{eval-rst}
+.. tabs::
+
+    .. group-tab:: Powershell
+
+        .. code-block:: powershell
+
+           > echo $LASTEXITCODE
+
+    .. group-tab:: Bash
+
+        .. code-block:: bash
+
+            $ echo $?
+
+    .. group-tab:: Command Prompt
+
+
+        .. code-block:: text
+
+            > echo %ERRORLEVEL%
+
+```

docs/index.rst

@@ -112,6 +112,7 @@ General Reference
    utils
    shell-completion
    exceptions
+   command-line-reference
    unicode-support
    wincmd