Isar is dead, long live Isar

### Current State
Obviously, Isar is abandoned by @simc

Obviously, Isar remains an exceptional piece of software

### Long live Isar
@Jtplouffe, as far as I can tell, you still have write access to the repository. Could we join forces with @vicenterusso and others who showed their interest through recent PRs to ensure Isar’s longevity and continued development?

### Why I refrain from using the Community Fork
There is a [Community Fork](https://github.com/isar-community/isar). led by @vicenterusso.
However, after reviewing it, I noticed some concerns (I may be wrong on some points):

- Pull requests being merged despite failed CI checks, indicating potential quality issues.
- A divergence in overall project standards and quality.
- Commit messages not adhering to conventional specifications.

### Some relevant Issues and PRs
Issues: #1686, #1685, #1679, #1678, #1675, #1673, #1672, #1655, #1652, #1647, #1640, #1625, #1601, #1564, #1560, …
PRs: #1688, #1659, #1599, #1569, …

No files, tests, or entry points are named. Start by reviewing the discussion and the referenced issues and pull requests, including #1688, #1686, and #1685. Done would require an agreed direction for Isar's continued maintenance and development.

Written by the indexing model from the issue text.