Add some links to the 'Edit the Documentation' section

[bstansberry]

Not urgent, e.g. not a blocker for cutting over to the new site. This is something the main wildfly devs can handle later if needed.

The 'Edit the Documentation' section on the contribute page could have a JIRA link for filing issues and/or a link to https://github.com/wildfly/wildfly/tree/master/docs to point to where the source for most documentation is.

[bstansberry]

Note that https://github.com/wildfly/wildfly.org/issues is where this should be tracked as this repo was for some initial site conversion development work and should now be archived.

Not sure what we want to do about this though as we are discussing refactoring how docs are produced and links we add are vulnerable to breakage if we do that.