v0.4.4 - docs

MPSKitModels v0.4.4

Diff since v0.4.3

Bump the TensorKit compat to v0.15

Merged pull requests:

• Bump actions/checkout from 4 to 5 (#56) (@dependabot[bot])
• CompatHelper: bump compat for TensorKit to 0.15, (keep existing compat) (#58) (@github-actions[bot])
• Some doc fixes and additions for spin operators (#59) (@leburgel)
• Switch to Runic formatter (#60) (@leburgel)