Need to update the GitHub link logic because its under Community

[RichieEscarez]

In the file below, the logic needs to point to knative/community for all but the code samples under the "Community" section on knative.dev

https://github.com/knative/website/blob/master/layouts/partials/page-meta-links.html#L49

Since Contributing was merged under Community, this condition no longer works:
{{ if eq $pageSection "contributing" }}

[RichieEscarez]

More content has been added to knative/docs that gets published under the "Community" section of the site in addition to the code samples ( like meetup and annual reports ). The fix is no longer straight forward given that half the content each live in different repos.

#211 fixed the original issue but there is more to do for stuff in https://github.com/knative/docs/tree/master/community

[RichieEscarez]

Related: knative/docs#3211