Run build during install and remove locales (#28)

* Run build during install

* Cleanup

Author: lipis

README.md

@@ -10,7 +10,19 @@
 
 ## Development
 
-Format all the supported files:
+First time:
+
+```
+yarn
+```
+
+Build:
+
+```
+yarn build
+```
+
+Format files:
 
 ```
 yarn fix

ext/_locales/en/messages.json

@@ -9,7 +9,6 @@
     "48": "icons/icon48.png",
     "128": "icons/icon128.png"
   },
-  "default_locale": "en",
   "background": {
     "page": "src/background/background.html",
     "persistent": true

ext/manifest.json

@@ -23,6 +23,7 @@
     "fix:other": "yarn prettier --write",
     "fix:js": "yarn test:js --fix",
     "fix": "yarn fix:js && yarn fix:other",
+    "install": "yarn build",
     "prettier": "prettier \"**/*.{md,css,html,json,yml}\" --write",
     "test:other": "yarn prettier --list-different",
     "test:js": "eslint --ignore-path .gitignore --ignore-path .prettierignore \"**/*.js\"",