Fix date in release notes (#1574)

Fix release date for v0.23.0.

Add release notes for v0.22.2 (#1532)

Add release notes for v0.22.2. Add v0.22.2 to `versions.json`.

Add latest merged PR to release notes for v0.22.1 (#1510)

Add #1509 to the release notes for v0.22.1.

Add release notes for v0.22.0 (#1499)

Add release notes for v0.22.0. Add new version to `versions.json` file
and mark it as the latest.

Add release notes for v0.21.1 (#1416)

Add release notes for patch `v0.21.1`.

Publish documentation on azure (#1412)

Adds a publish step on the documentation test CI so we can download it and
view it.

Merge pull request #1282 from mplough-kobold/main

Refresh links in documentation

Merge pull request #1275 from jcapriot/0.20.0_staging

0.20.0 staging

Bump version: 0.18.1 → 0.19.0

Bump version: 0.18.0 → 0.18.1