docs(core): clarify polish.lua documentation

lua/polish.lua

@@ -1,9 +1,2 @@
--- if true then return end -- WARN: REMOVE THIS LINE TO ACTIVATE THIS FILE
-
 -- This will run last in the setup process.
--- This is just pure lua so anything that doesn't
+-- Pure lua; anything that doesn't fit the normal config locations goes here.
--- fit in the normal config locations above can go here
---
---
-
-