[docs] Adding Initial Documentation (#3139)

## Overview
Adding Markdown, simplified versions of the docs hosted on [External Site](https://evilperson1337.notion.site/Eden-Guides-2b057c2edaf680149310edee3024565d).

### Guides Added

- Adding Games into Steam with Steam ROM Manager and Eden
- Adding Eden as an emulator into Steam ROM Manager
- How to modify the Date/Time in Eden
- How to configure controller profiles
- How to set controller profiles per game
- Eden fails to launch but does not leave a log (Windows)
- How to configure motion/gyro controls on steam deck
- How to access logs
- How to import saves into Eden (windows)
- How to install Atmosphere mods
- How to install Updates/DLC
- Quick Start Guide (Steam Deck)
- Quick Start Guide (Windows)
- Allowing Eden to Run on MacOS (MacOS)
- Sync Game Saves with Syncthing (General)
- Sync Game Saves with Syncthing (Windows)
- Sync Game Saves with Syncthing (Linux)
- Using Amiibo with Eden (Windows)
- Using Cheats with Eden (Windows)
- Using Cheats with Eden (Android)

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3139
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Co-authored-by: Evilperson1337 <Evilperson1337@proton.me>
Co-committed-by: Evilperson1337 <Evilperson1337@proton.me>

docs/user/QuickStart_SteamDeck.md

@@ -0,0 +1,42 @@
+# Eden Quick Start
+
+Use this guide to get starting using the Eden emulator on Steam Deck.
+
+**Click [Here](https://evilperson1337.notion.site/Eden-Quick-Start-2b757c2edaf680d49ffdcda291a32840) for a version of this guide with images & visual elements.**
+
+---
+
+### Pre-Requisites
+
+- Firmware dumped from your console
+- Keys extracted from your console
+- Games dumped from your console
+- Internet Connection
+
+---
+
+## Steps
+
+1. Access Steam Desktop Mode.
+2. Download either the *Stable* or *Nightly* Eden AppImage onto your Steam Deck and save it somewhere accessible.
+    
+    <aside>
+        
+    ***TIP***:  If you have questions about the requirements, architectures, or general information surrounding what release you need - see the [*Basics Guide*](./Basics.md) and [*Architectures Guide*](./Architectures.md).
+        
+    </aside>
+    
+3. Double-Click the Eden executable to launch the program.
+    <aside>
+
+    ***NOTE***: The first time you run the AppImage you will get a notification asking you to confirm you want to launch the program.  Hit **Continue**.
+
+    </aside>
+    
+4. If you have had a different Switch emulator installed, it will detect and ask if you want to import those settings.  Make your selection to close the screen.
+5. Eden will now launch and notify you about missing Encryption keys. Close the dialog box by hitting **OK**.
+6. Navigate to **Tools → Install Decryption Keys**, navigate to the folder containing your ***prod.keys*** file and select the file and hit **Open**.
+7. Navigate to **Tools → Install Firmware →** *Select **From Folder*** or ***From ZIP*** - depending on how your firmware is stored, navigate to where it is stored and select it.
+8. Double-Click the main window to add the folder containing your games.
+9. Go to *Emulation > Configure > Input* and set up your controller. Click **OK** to close the dialog window.
+10. Double-Click a game to run it.