Add translation guide and fix Gentoo instructions

.github/CONTRIBUTING.md

@@ -62,6 +62,25 @@ License 2.0, without any additional terms or conditions. By using,
 redistributing, or modifying it, you must agree to the license,
 and the additional clauses provided [in the README file](../README.md#License).
 
+## Translations
+
+You can contribute translations on [Crowdin](https://crowdin.com/project/firefoxpwa).
+Please make sure you write your messages correctly and in a consistent style. If
+you have any questions or suggestions, both for new and existing translations and
+messages, please use Crowdin's discussions feature to communicate with others.
+
+If your language is not yet available, please contact me on Crowdin.
+
+*Note:* The localization feature is currently still work-in-progress, and not many
+strings are available for translation. Proper localization is being worked on.
+Please follow the Crowdin project for updates and new available messages.
+
+<details>
+  <summary>Expand localization status</summary>
+
+[![Localization status](https://badges.awesome-crowdin.com/translation-13220281-466834.png)](https://crowdin.com/project/firefoxpwa)
+</details>
+
 ## Code of Conduct
 
 This project adheres to [the Contributor Covenant Code of Conduct](https://www.contributor-covenant.org/version/2/0/code_of_conduct/).

README.md

@@ -5,7 +5,7 @@ Progressive Web Apps for Firefox
 
 [![Release](https://img.shields.io/github/v/release/filips123/PWAsForFirefox?sort=semver&style=flat-square)](https://github.com/filips123/PWAsForFirefox/releases/latest)
 [![Users](https://img.shields.io/amo/users/pwas-for-firefox?style=flat-square)](https://addons.mozilla.org/firefox/addon/pwas-for-firefox/)
-[![Rating](https://img.shields.io/amo/rating/pwas-for-firefox?style=flat-square)](https://addons.mozilla.org/firefox/addon/pwas-for-firefox/)
+[![Rating](https://img.shields.io/amo/rating/pwas-for-firefox?style=flat-square)](https://addons.mozilla.org/firefox/addon/pwas-for-firefox/reviews/)
 [![License](https://img.shields.io/github/license/filips123/PWAsForFirefox?style=flat-square)](https://github.com/filips123/PWAsForFirefox/blob/main/LICENSE)
 [![Repositories](https://img.shields.io/repology/repositories/firefoxpwa?style=flat-square)](https://repology.org/project/firefoxpwa/versions)
 [![Packagecloud.io DEB](https://img.shields.io/badge/deb-packagecloud.io-844fec.svg?style=flat-square)](https://packagecloud.io/filips/FirefoxPWA)

extension/src/setup/instructions.html

@@ -135,8 +135,9 @@
 
         <div class="tab-pane fade" id="linux-gentoo-install-pane" role="tabpanel" aria-labelledby="linux-gentoo-install-tab">
           <ol>
-            <li>Enable Gentoo GURU overlay using eselect: <kbd>eselect repository add guru</kbd></li>
-            <li>Install the package using emerge: <kbd>emerge -avt www-plugins/firefoxpwa</kbd></li>
+            <li>Enable Gentoo GURU overlay using eselect: <kbd>sudo eselect repository enable guru</kbd></li>
+            <li>Sync Gentoo GURU overlay using emerge: <kbd>sudo emerge --sync guru</kbd></li>
+            <li>Install the package using emerge: <kbd>sudo emerge -avt www-plugins/firefoxpwa</kbd></li>
             <li>After the package is installed, you should be automatically proceeded to the next step. If nothing changes after around 30 seconds, restart the browser.</li>
           </ol>
           <p class="ps-3">