Launchpad: Add an info box on the discontinuation of support for Bazaar

Background

Launchpad is in the process of discontinuing support for Bazaar. Bazaar has largely fallen out of favor, but is still used by some individuals and communities. From September 1st, 2025, users will not have access to Bazaar. They are, therefore, advised to migrate their repositories to Git before the deadline.

Task

Add an info box in docs that make reference to Bazaar letting users know that it is being discontinued. Due to the number of docs affected, this should not be done manually in every doc. Add an appropriately named .rst file in the /includes folder and reference this file near the top of each affected doc (preferably under any includes already present).

The text in the info box must:

• Inform users that Bazaar is being discontinued
• Tell affected users to migrate their code from Bazaar to git and the deadline for migration
• Link to this page
• Not be longer than two lines

To preview the expected result, check the existing files in the Launchpad manual /includes folder.