added discord server to readme.md

Author: TrainzMarcel

README.md

@@ -23,6 +23,10 @@ and [plugin/lua\_repl.lua](plugin/lua_repl.lua).
 Currently, only LuaJIT is supported, since the implementation is based on its
 [FFI](https://luajit.org/ext_ffi.html) library.
 
+We also have a discord server:
+
+[![Pluginscript Lua](https://img.shields.io/discord/1056941025559588874.svg?label=Discord&logo=Discord&colorB=7289da&style=for-the-badge)](https://discord.gg/rZJbXZXQWe)
+
 
 ## Installing