Docs: In CLI messages, compose URLs with app's minor version

## Background

With `render_doc_url`, the version in doc URLs takes into account the patch version:

https://github.com/canonical/craft-application/blob/fb5998d97b1cccd068843615047de9c75aeb1cc4/craft_application/util/docs.py

When we move to minor-only RTD versions, these paths won't be available anymore.

## Request

In alignment with our near-term plans of only publishing docs as minor versions, this function should substitute the minor version of the built app.

Start in craft_application/util/docs.py at render_doc_url and inspect how it currently builds the documentation URL from the app version. Update the behavior so generated CLI documentation URLs use the app's minor version rather than its patch version, then verify the resulting paths match the minor-only Read the Docs versions described in the issue.

Written by the indexing model from the issue text.