Please consider adding a 'keywords' or 'tags' section in metadata.json

We'd like our team's Azure RM templates to be searchable using some specific keywords (and their variants). We generally put the keywords in the "itemDisplayName", "description", "summary" fields of the metadata.json file.

However we also want the templates to be discoverable when are some variants of these keywords are used. As an example:
- "Azure DevTest Labs" (primary keyword)
- "Azure Dev/Test Labs" (variant of primary keyword)
- "Azure Dev Test Labs" (variant of primary keyword)

It'd be great if we had a a keyword or tags section in the metadata.json file to support these.

CC: @ryanvog @ramankumarlive @mmydland

Start by reviewing how metadata.json is structured and used for Azure RM template discovery. Determine how a keywords or tags section would represent primary terms and variants, and define what successful discoverability should mean before proposing the metadata change.

Written by the indexing model from the issue text.