fix(cli): add user feedback when opening config docs in browser

The config:docs command previously only logged 'Loaded config from
app-config.yaml' and silently attempted to open the browser, providing
no feedback about what was happening. This change adds clear console
output to indicate the browser is being opened and displays the URL.

This approach provides better user experience by:
- Showing users that the command is attempting to open their browser
- Displaying the full URL being opened for transparency
- Providing fallback instructions if the browser fails to open

Fixes #29512

Signed-off-by: Josephine Pfeiffer <hi@josie.lol>
