doc: Categorize connectors

[hariso]

Categorizing connectors might make it easier for connectors to be discovered. E.g.

• AWS
• GCP
• Relational databases
• etc.

[raulb]

If we believe this categorization is relevant, I think the work would be done as part of ConduitIO/conduit#1523.

Before we get into that, I believe we need to ensure that the categorization makes sense. In particular, what would be included in etc. so every possible connector has a category that's intuitive.

Maybe, we could have these categorization as tags, so those would be used to filter them out on the UI.

E.g.:

# connector.yaml
version: 1.0
connector:
  name: postgres
  author: Meroxa, Inc.
  version: v1.0.0
  summary: ...
  tags:
    - relational database
  description: |
    ...
  # ------------------------ GENERATED ------------------------
  ...

If we go in that direction, we need to make sure we don't add tags freely, but rather try to use any other previously created ones so the categorization is actually useful.