Document BIM working plane restore fix

[100more]

Document BIM working plane restore fix

Summary

• Add a FreeCAD 1.2 BIM release-note entry for BIM: restore working plane after recentering FreeCAD/FreeCAD#28836.
• Keep translation files untouched; the PR now only updates the source release-note page.
• Keep the change scoped to release notes; no command pages or generated content are edited.

Contributes to #26.
Contributes to #30.

Why this is low-risk

• Documentation-only change.
• Uses the same bullet and upstream pull-request link style already present in the file.
• Touches only wiki/Release_notes_1.2.wikitext after maintainer feedback.

Files changed

• wiki/Release_notes_1.2.wikitext - modified: Adds the BIM working-plane restore release-note bullet.

Coverage

• Checked this is not covered by an existing open documentation PR for PR #28836, recentering, or working-plane restore.

Verification

• git diff --check origin/main...HEAD - passed

Reviewer notes

• I removed the wiki/en/Release_notes_1.2.wikitext change in response to the translation-file guidance.

Boundary note

No payment, account, secret, or private contact details are included in this PR.

[Reqrefusion]

"en" files should not be modified. All translation files should remain untouched.

[100more]

Thanks for the review. I updated the branch so translation files are untouched now:

• removed the wiki/en/Release_notes_1.2.wikitext change from the PR diff
• kept the release-note entry only in wiki/Release_notes_1.2.wikitext
• re-ran git diff --check origin/main...HEAD

Happy to adjust anything else that would make this easier to merge.

[Reqrefusion]

Do not add T tags yourself; only modify the files in the wiki root directory, do not touch the translation files. Please check the latest version and ensure that the information you are adding has not been added previously. Also, be sure to cite the source of your change. Regression corrections should not be added to the documentation. And it should never contain information that the end user shouldn't know.