Reduce reliance on external web resources (#1093)

Signed-off-by: Daniel Gray <dng@disroot.org>

docs/android.en.md

@@ -53,7 +53,7 @@ Currently, CalyxOS only supports [Pixel phones](https://calyxos.org/docs/guide/d
 
     ![DivestOS logo](assets/img/android/divestos.svg){ align=right }
 
-    **DivestOS** is a [soft-fork](https://en.wikipedia.org/wiki/Fork_(software_development)#Forking_of_free_and_open-source_software) of [LineageOS](https://lineageos.org/).
+    **DivestOS** is a soft-fork of [LineageOS](https://lineageos.org/).
     DivestOS inherits many [supported devices](https://divestos.org/index.php?page=devices&base=LineageOS) from LineageOS. It has signed builds, making it possible to have [verified boot](https://source.android.com/security/verifiedboot) on some non-Pixel devices.
 
     [Visit divestos.org](https://divestos.org){ .md-button .md-button--primary } [Privacy Policy](https://divestos.org/index.php?page=privacy_policy){ .md-button }
@@ -103,7 +103,7 @@ The installation of GrapheneOS on a Pixel phone is easy with their [web installe
 A few more tips for purchasing a Google Pixel:
 
 - If you're after a bargain on a Pixel device, we suggest buying an "**a**" model, just after the next flagship is released. Discounts are usually available because Google will be trying to clear their stock.
-- Consider price beating options and specials offered at [brick and mortar](https://en.wikipedia.org/wiki/Brick_and_mortar) stores.
+- Consider price beating options and specials offered at brick and mortar stores.
 - Look at online community bargain sites in your country. These can alert you to good sales.
 - Google provides a list showing the [support cycle](https://support.google.com/nexus/answer/4457705) for each one of their devices. The price per day for a device can be calculated as: $\text{Cost} \over \text {EoL Date }-\text{ Current Date}$, meaning that the longer use of the device the lower cost per day.
 
@@ -300,7 +300,9 @@ The Google Play Store requires a Google account to login which is not great for
 
 ### F-Droid
 
-F-Droid is often recommended as an alternative to Google Play, particularly in the privacy community. The option to add third party repositories and not be confined to Google's [walled garden](https://en.wikipedia.org/wiki/Closed_platform) has led to its popularity. F-Droid additionally has [reproducible builds](https://f-droid.org/en/docs/Reproducible_Builds/) for some applications, and is dedicated to free and open source software. However, there are problems with the official F-Droid client, their quality control, and how they build, sign and deliver packages, outlined in this [post](https://wonderfall.dev/fdroid-issues/).
+F-Droid is often recommended as an alternative to Google Play, particularly in the privacy community. The option to add third party repositories and not be confined to Google's walled garden has led to its popularity. F-Droid additionally has [reproducible builds](https://f-droid.org/en/docs/Reproducible_Builds/) for some applications, and is dedicated to free and open source software. However, there are problems with the official F-Droid client, their quality control, and how they build, sign and deliver packages, outlined in this [post](https://wonderfall.dev/fdroid-issues/).
+
+*[walled garden]: A walled garden (or closed platform) is one in which the service provider has control over applications, content, and/or media, and restricts convenient access to non-approved applicants or content.
 
 Sometimes the official F-Droid repository may fall behind on updates. F-Droid maintainers reuse package IDs while signing apps with their own keys, which is not ideal as it does give the F-Droid team ultimate trust. The Google Play version of some apps may contain unwanted telemetry or lack features that are available in the F-Droid version.