pug-lexer loc with source endings (#2957)

* Ignore VSCode files

* Use `loc` on lexer tokens to store source location information

* Update pug-parser and pug to use new `loc` attribute on tokens

* Update parser test cases to have new `loc` attribute on tokens

* New lexer snapshots

* New parser snapshots

* PR review changes
- remove no-ops
- rename `attributeName` to `attribute`
- attributeName no longer takes a tok and returns a reponse object
- minor cleanup

.gitignore

@@ -1,5 +1,6 @@
 .DS_Store
 .idea
+.vscode
 testing
 node_modules
 lib-cov