[docs] initial user handbook draft (#2629)

This is the initial draft of a "User Handbook", or FAQ. Currently contains useful info on the basics, graphics, and architecture/platform info.

Archive.org OR archive.is should be used for linking external websites, especially since their content should not change. And most often than not, in a few years these could change.

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Co-authored-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2629
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

docs/User.md

@@ -1,11 +1,10 @@
-# User configuration
+# User Handbook
 
-## Configuration directories
+The "FAQ".
 
-Eden will store configuration in the following directories:
+This handbook is primarily aimed at the end-user - baking useful knowledge for enhancing their emulation experience.
 
-- **Windows**: `%AppData%\Roaming`.
-- **Android**: Data is stored internally.
-- **Linux, macOS, FreeBSD, Solaris, OpenBSD**: `$XDG_DATA_HOME`, `$XDG_CACHE_HOME`, `$XDG_CONFIG_HOME`.
-
-If a `user` directory is present in the current working directory, that will override all global configuration directories and the emulator will use that instead.
+- **[The Basics](user/Basics.md)**
+- **[Audio](user/Audio.md)**
+- **[Graphics](user/Graphics.md)**
+- **[Platforms and Architectures](user/Architectures.md)**