Update README.md [ci skip]
Update README.md [ci skip]

* No need to install LuaLanes from a fork for Lua 5.3 support anymore;
* Better basic usage.

xpol/luacheck,linuxmaniac/luacheck,tst2005/luacheck,linuxmaniac/luacheck,xpol/luacheck,mpeterv/luacheck,mpeterv/luacheck,kidaa/luacheck,xpol/luacheck,adan830/luacheck,adan830/luacheck,tst2005/luacheck,mpeterv/luacheck,kidaa/luacheck