configuration instructions should point to starter.lvim

[kylo252]

Hi, this change is very confusing especially when the docs say to copy this file to get started and then the file only contains links back to that same documentation. Its extremely confusing for new users. I had to go back in git history to understand what config to use.

Originally posted by @jgoulah in LunarVim/LunarVim#4128 (comment)