Add search functionality

[rvd]

i.e.
$ sam search "keyword"

keyword would then be matched against title and description of all published packages.

$ sam info "package"
could be a printout of description and dependencies

I suspect the grimoire was originally meant to be more than just a collection of Origins, and descriptions longer than one line would perfectly fit in the formula yaml files.

As it is now, no formula has descriptions, so on "sam update" a library/index or stub file could be created/updated which holds at least a description of every package copied from the usefile of that package. This index could then be used for the search.

[nddrylliog]

Indeed, the library should ideally contain more than origins, such as descriptions, homepages, etc. As for having a local index to speed up search, that could be for a v2 of the search feature - seeing as the number of formulas is quite low for the time being, even a plain text search would work (afaict homebrew doesn't have an index file, just flat files for each formula and it does the search in that).