docs: backdated and new release notes

[hieblmi]

This PR adds a docs/release-notes folder and adds backdated release notes.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.

[starius]

It should be not the template here. We need another growing file for a future release. Like docs/release-notes/release-notes-next.md

[starius]

Missing releases: v0.1.3-beta, v0.2.0-alpha, v0.6.1-beta, v0.15.1-beta, v0.25.0-beta, v0.25.1-beta, v0.26.1-beta, v0.31.3-beta, v0.31.5-beta-lnd0.20, and v0.31.6-beta.

Consequently, previous/next navigation also skips real tags, for example v0.6.0-beta jumps directly to v0.6.2-beta, and there some issues with particular releases:

• v0.25.2 notes compare against v0.24.1, assigning PRs Migrate from boltdb to sql #585, Easy autoloop feeppm parameter #595, and multi: expose L402 id in grpc interface #601 to v0.25.2. Those landed before v0.25.0; the actual v0.25.1...v0.25.2 delta only removes unsupported release platforms and bumps the version. Its contributor list is consequently also overinclusive.
• v0.31.4 notes skip v0.31.3 and claim PR staticaddr: fractional swap amount #887 as a v0.31.4 feature, although staticaddr: fractional swap amount #887 is the commit tagged as v0.31.3. See the true delta.
• v0.31.7 notes assign peer exclusions, loop stop, startup fixes, and dependency updates to v0.31.7. They were already in v0.31.6; the actual v0.31.7 delta is only the version bump. Under the index's stated contributor rule, that page should contain only Alex Bosworth, not five contributors.

v0.34.0-beta is already released, but it is accounted as "Unreleased".

The v0.1.1 build block extracts loop-source-v0.1-alpha and embeds Commit=v0.1-alpha. The v0.2 similarly asks for v0.1-alpha manifests/source and builds with the old tag. These errors existed in the historical prose, but reproducing them makes the new archive factually unsafe; they should be corrected or omitted while retaining the historical release ideas.

[hieblmi]

Thanks for the detailed review @starius, I've addressed all issues you found!