v0.12.0

TensorKit v0.12.0

Diff since v0.11.2

Merged pull requests:

• Fermion Refactor (#81) (@lkdvos)
• Automatic Differentiation (#82) (@lkdvos)
• Remove field type-parameter for vectorspaces (#83) (@lkdvos)
• CompatHelper: add new compat entry for PackageExtensionCompat at version 1, (keep existing compat) (#84) (@github-actions[bot])
• Cherry-pick small fixes (#87) (@lkdvos)

Closed issues:

• Inconsistent behaviour for tensor contraction (#80)