Fixing up some typos and issues with the new tooling docs
Merge branch 'master' of github.com:google/WebFundamentals

* 'master' of github.com:google/WebFundamentals:
  fix for #861 #863 #862
  Fix issue #870
  fixing og:image url for social site sharing
  revert .gitignore to previous version git
  rename performance/performance/critical-rendering-path -> performance/critical-rendering-path
  fix typo in config files and delete trash file
  translated performane/critical-rendering-path/index.markdown
  Update the schema link for the Github sample
  Translation: /fundamentals/performance/index.markdown