Clarify _ENV issues

Author: vallode

README.md

@@ -57,7 +57,7 @@ These definitions require [`lua-language-server`](//github.com/LuaLS/lua-languag
 - Developing the DFHack lua library with the annotations loaded can be annoying due to "duplicate field" warnings
 - DFHack's C++ functions that are exposed to Lue are **not included** (#4)
 - Initally opening DFHack can take a long time to load, especially on weaker hardware (#5)
-- LuaLS has a known problem with type-hinting inside of files that write to the `_ENV` global
+- LuaLS has a known problem with type-hinting inside of files that write to the `_ENV` global, if you are in a file writing to `_ENV` comment out those lines.
 
 ## Credits