Fix: Only show welcome message when notes location is not configured

[Blogem]

Summary: This pull request refines the welcome experience in the Notes view by conditionally displaying the "Select Location" prompt. Previously, the prompt remained visible even after a notes location was configured, making it harder for users to notice the available action buttons at the top.

Changes:

• The welcome message in the notes view now only appears when config.notes.notesLocation is unset or empty.
• Once a notes location is configured, the prompt is hidden, making the action buttons more discoverable and improving overall usability.

Related issues:

• #71
• #69