This cleans up all of the usage of `<a>` in the codebase. Now all
external links get the appropriate attributes added.

Depends on https://github.com/actualbudget/docs/pull/202.

Seems to build fine, will test later.

*  (prettier) adding trailing commas

* More commas

The Actualbudget blog no longer exists, replaced the links with the OSS release notes.

* style: enforce ordering of imports

* style: sort imports in loot-core

* style: sort imports in desktop-client

* style: sort imports in loot-design

* style: manual fixes