chore: release 1.2.0

[github-actions[bot]]

:robot: I have created a release *beep* *boop*

1.2.0 (2022-01-08)

Features

• Support mirrors from maven settings.xml (1f644aa)

Bug Fixes

• copy over non-enumerable playbook.env to play nice with lunr (1f644aa)

This PR was generated with Release Please. See documentation.

[github-actions[bot]]

:robot: Release is at https://github.com/kiwigrid/antora-maven-content-extension/releases/tag/v1.2.0 :sunflower: