FLUID-6324: use @waharnum's fork of docpad-plugin-handlebars

[waharnum]

I've fixed the Handlebars plugin for the 6.82.x line of Docpad.

I will open a pull request to the plug-in to discuss my fix and potentially get it merged upstream, but for now this allows the docs site to be generated with the 6.82.x line of Docpad.

My PR at docpad/docpad-plugin-handlebars#13 - we can update our use of the plugin should that get merged.

[jobara]

@waharnum thanks for providing this stop gap while we wait for them to merge your PR.

[waharnum]

As noted in our convo, this doesn't work in current state because of the compile step that happens (typically) as part of the plug-in publishing to NPM.

Working around this is probably a matter of publishing a branch with the compile step completed (publishing our own version to NPM seems like overkill).

[jobara]

If we end up publishing to NPM we should publish it as an org scoped package ( https://docs.npmjs.com/creating-and-publishing-an-org-scoped-package )