Add way to search within your collections

[cbetta]

Will probably require

• [ ] Some way to have meta data (name, description, tags) on a template (comment at start of file?)
• [ ] Loop over all and select all that match

Additionally it would be cool if we

• [ ] Allow user to search on remote repositories too
• [ ] Have remote repositories managed by a file on github (e.g. in a new repo name primo-collections)