Delete documentation and website source (#11137)

* Deleted docs folder

* Deleted www folder

* Remove Netlify website build command

* Removed refs to docs and www from ESlint config

* Removed refs to www/docs from Flow config

* Removed unnecessary .gitignore config

* Updated license check to remove refs to docs

* Removed gh-pages specific portions of Circle build scripts
There may be more that we can remove (eg set_up_github_keys.sh) but I'm not positive

* Removed docs specific license