Eslint fixes

[emackey]

Fixes #158, there should be no more eslint messages after this.

• new operator is specifically allowed to construct classes beginning with lowercase gl
• Windows platforms use LF for (js, json, html, css) files now, to enforce line endings (old repos on Windows before this change will need to delete and reset, or re-clone these files, to get clean LF copies).
• VSCode extension recommendations added: ESLint, a shader syntax highlighter, and glTF Tools
• List of eslint included & excluded files tweaked

[donmccurdy]

I think we should rename the gl classes at some point... they read very awkwardly to me, and I don't think matching the glTF capitalization in code is worthwhile.

[emackey]

Out of scope for this PR, but yes I agree.