Update/remove/edit a few assistance commands (#1233)

* assistance: update `android` to A11

* assistance: remove trimgame.dsi, make 3DS the default

Effectively it's the same for both.

* tutorial: combine themes.switch with `tag nxthemes`

Now it links the guide as well as where to get themes

cogs/assistance-cmds/android.switch.md

@@ -1,6 +1,6 @@
 ---
-title: Android 10 Setup Guide
-url: https://wiki.switchroot.org/en/Android/Setup-10.html
+title: Android 11 Setup Guide
+url: https://wiki.switchroot.org/Android/Setup-11.html
 thumbnail-url: https://gitlab.com/uploads/-/system/group/avatar/4623003/switchroot.png
 author.name: Switchroot
 help-desc: Guide to set up Android on a Nintendo Switch

cogs/assistance-cmds/tutorial/themes.switch.md

@@ -1,9 +1,11 @@
 ---
-title: Switch Themes Tutorial
-url: https://nh-server.github.io/switch-guide/extras/theming/
+title: Switch Themes
 help-desc: Links to tutorials for installing themes
-aliases: theme
-color: A84300
 ---
 
-Tutorial for installing themes on the Switch
+[Theme installation guide](https://nh-server.github.io/switch-guide/extras/theming/)
+
+Theme repositories:
+- [themezer](https://themezer.net/)
+    - [Homebrew app version](https://github.com/suchmememanyskill/themezer-nx/releases)
+- [r/NXThemes](https://www.reddit.com/r/NXThemes/)