[+] Docs

docs/chu3-national-matching.md

@@ -1,4 +1,31 @@
 # Chunithm National Matching Guide
 
-TODO
+The national matching game mode allows up to 4 players on any server (YES, ANY SERVER) to play together.
+In this game mode, for example, you can play with RinNET or Missless players as well.
+This is a guide on how to set up your client for national matching.
 
+## Pre-requisites
+
+- Play the normal game at least once so that you have a profile on the server.
+
+## Setting Up
+
+1. Make sure you use [Dniel97's open-source segatools](https://gitea.tendokyu.moe/Dniel97/SEGAguide/wiki/SDHD)
+   If you're using fufubot segatools, please override it with Dniel97's version (don't forget to update `segatools.ini`).
+2. Patch your `chusanApp.exe` using [Two-Torial's open-source patcher](https://patcher.two-torial.xyz/)  
+   (Make sure you disable "Set all timer to 999", enable "No encryption", "No TLS", "Patch for head-to-head play")
+3. Make sure you only have official options.  
+   (Remove things like A999, AOMN, etc.)
+4. Pet your cat 🐈
+5. Launch!
+
+## How to Play
+
+When you enter the matching mode, it will assign to you a matching room if other people are online, or create a new room otherwise. 
+Then, after four people are present or after a specific amount of time has passed, the game will start.
+Everyone will be asked to pick a song at the start, even though your song might not be the first one to be played.
+After songs are picked, other players will play the song on the SAME DIFFICULTY as what you picked.
+(So be a nice person and don't pick 15 if there are new players alright? 🥺)
+
+If there are less than 4 players when the timer runs out, the game will fill in the empty slots with bots.
+The bots will randomly select a song (mostly under Lv10).