Create a CLI command to search through repositories

[Blokje5]

The search command will help users find policies that are related to their use case. At a minimum the search command should support searches based on the following matches:

• Search on repository name
• Search on Keywords

And ideally also support searches based on Description

We can use e.g. https://github.com/blevesearch/bleve/ to create a searchable index of the available data.