Source for creating dll lua module.
1. Download and unpack folder.
2. Add files to your IDE as dll project.
3. Select release and architecture (Default gmod - x86, chromium - x64), disable precompiled headers.
4. Add includes to project and put needed lib to source files.
5. Change in api.h XX to your selested architecture.
6. Register new app on discord.com/developers/applications/ and copy clientID.
7. Change in rpc.cpp YOUR_RPCAPP_CLIENTID to clientID your application.
8. Compile project and rename output dll as gmcl_dllname_winXX.dll, where dllname - want name, XX - project settings(86/64).
9. Move renamed dll to ...\GarrysMod\garrysmod\lua\bin\ and lua folder to ...\GarrysMod\garrysmod\
Lua script contains client cvar discordrpc_enabled for disable/enable rpc from game.