Changes to Firefox, Safari, Adguard cards (#719)

_data/software/browsers-desktop/1_firefox.yml

@@ -36,6 +36,12 @@ description: |
     <li>Select: <strong>Enable HTTPS-Only Mode in all windows</strong>.</li>
   </ul>
 
+  #### Sync
+  The [Firefox sync](https://hacks.mozilla.org/2018/11/firefox-sync-privacy/) service is end-to-end encrypted.
+
+  #### Extensions
+  We generally do not recommend installing any extensions as they increase your [attack surface](https://en.wikipedia.org/wiki/Attack_surface); however, if you want content blocking, [uBlock Origin](/browsers/#additional-resources) might be useful to you. The extension is also a 🏆️[Recommended Extension](https://support.mozilla.org/kb/add-on-badges#w_recommended-extensions) by Mozilla.
+
   #### Arkenfox (advanced)
   The [Arkenfox project](https://github.com/arkenfox/user.js) provides a set of carefully considered options for Firefox. These options are quite strict but a few are subjective and may cause some websites to not work properly. You can easily change these settings to suit your needs. We **strongly recommend** reading through their [wiki](https://github.com/arkenfox/user.js/wiki). Arkenfox also enables [container](https://support.mozilla.org/en-US/kb/containers#w_for-advanced-users) support.
 

_data/software/browsers-mobile/2_safari.yml

@@ -12,7 +12,6 @@ description: |
   </ul>
 
   ##### **Privacy Preserving Ad Measurement**
-
   This is Apple's own implementation of private ad tracking. If you don't wish to participate, you can disable this feature.
 
   <ul style="list-style-type:none;padding-left:0;">
@@ -20,7 +19,6 @@ description: |
   </ul>
 
   ##### **Apple Pay**
-
   If you do not use Apple Pay, you can toggle off the ability for websites to check for it.
 
   <ul style="list-style-type:none;padding-left:0;">
@@ -28,13 +26,18 @@ description: |
   </ul>
 
   ##### **Always-on Private Tabs**
-
   Open Safari and press the tabs button at the bottom right corner. In the bottom middle press the downward facing arrow.
 
   <ul style="list-style-type:none;padding-left:0;">
     <li>Select: <strong>Private</strong>.</li>
   </ul>
 
+  #### Sync
+  The synchronization of data is end-to-end encrypted. Safari does not encrypt bookmarks and they are accessible to Apple.
+
+  #### Extensions
+  We generally do not recommend installing [any extensions](https://www.sentinelone.com/blog/inside-safari-extensions-malware-golden-key-user-data/) as they increase your browser's [attack surface](https://en.wikipedia.org/wiki/Attack_surface); however, if you want content blocking, [AdGuard for Safari](/browsers/#additional-resources) might be useful to you.
+
 website: https://www.apple.com/safari/
 privacy_policy: https://www.apple.com/legal/privacy/data/en/safari/
 downloads:

_data/software/browsers-resources/2_adguard.yml

@@ -0,0 +1,13 @@
+title: AdGuard for Safari
+type: Recommendation
+logo: /assets/img/browsers/adguard.svg
+description: |
+  **AdGuard for Safari** is a free and open-source) content-blocking extension for Safari that uses the native [Content Blocker API](https://developer.apple.com/documentation/safariservices/creating_a_content_blocker).
+
+  There is also [AdGuard for iOS](https://adguard.com/en/adguard-ios/overview.html) which is able to perform system wide adblocking.
+website: 'https://adguard.com/en/adguard-safari/overview.html'
+downloads:
+  - icon: fab fa-app-store-ios
+    url: 'https://apps.apple.com/app/adguard-for-safari/id1440147259'
+  - icon: fab fa-github
+    url: 'https://github.com/AdguardTeam/AdGuardForSafari'