Lispy grammar parser

Summary:
Grammar parsers for Lispy language (it's a lisp) - to be used later to
1) extract meaningful data from binding scripts
2) better presentation of the scripts

There a are two parsers - one is transforming lispy to 'honest', raw tree
Another one does some simplifications - unwrap consts,arrays and maps

It uses https://nearley.js.org/docs/grammar parser and moo lexer

Reviewed By: yousuf-haque

Differential Revision: D26422882

fbshipit-source-id: 09c8aa91b635e4605104f9a52fa4699b53990006

desktop/.eslintignore

@@ -13,3 +13,4 @@ scripts/generate-changelog.js
 static/index.js
 static/defaultPlugins/index.json
 app/src/defaultPlugins/index.tsx
+generated