Updated README.md to emphasize .hlint.yaml more.
Updated README.md to emphasize .hlint.yaml more.

I am using hlint via Emacs extension and I had problems with hlint throwing parse error on QuasiQuotes.
Although I read the docs, it took me long time to figure out I had to create .hlint.yaml and add the line to it -> I had to find the solution in one of the issues on this repo.

Therefore, I tried here to explain better in "parse error" part of the faq that solution could be modifying .hlint.yaml. I also tried to emphasize more in the "install" part of the docs that .hlint.yaml exists, and I linked to it.

I know it is mentioned in the usage part, but there it is mentioned in the context of ignoring current warnings, which I didn't want and therefore I ended up not thinking .hlint.yaml is important. Any more details are in the faq and I don't normally read faq until I have some problems.
ndmitchell/hlint,ndmitchell/hlint