Enhancement Suggestion: WIKI Style Tags/Categories for user curation

[TotallyInformation]

See https://groups.google.com/forum/#!topic/node-red/J-6PWWgCNNo

Neil Kolban has suggested that it would be a nice idea to have the ability to curate groups/categories of nodes.

This probably needs an enhancement to this code to add some form of additional categorisation. That could then be used to automatically generate category pages that would pick up some additional descriptive text. Similar to the way that Wordpress and Stack Overflow work.

Questions:

1. How should the categories be curated? Should there be some user-level curation? Perhaps adding the capability for approved editors? Or should the categories be baked into the site with changes controlled via GitHub pull requests? A hybrid approach might be to allow any category/tag but to curate the descriptions. This is how Stack works.
2. Categories or Tags? Typically with Categories, you only have one. Tags tend to be more free-form.
3. Should the categories/tags be defined by the node creator? For example as part of the package.json. Or again, should this be separate with perhaps user curation? (though this might add significant admin overheads).

Anything else needed? I can update this to reflect updates/suggestions in further comments so we end up with a final suggestion if that is helpful.