Document BIM DrawingView cut line width

[newmattock]

Summary:
Adds a FreeCAD 1.2 release-note entry for FreeCAD/FreeCAD#30149.

Related bounty or issue:
Refs #30.

What changed:

• Documented that BIM DrawingView cut lines now use the default line width and cut areas line thickness ratio preferences for thicker cut-line output.
• Kept the update limited to the root Release_notes_1.2 page.

Validation:

• git diff --check -- wiki/Release_notes_1.2.wikitext
• Confirmed the upstream PR reference appears once.
• Confirmed translate tag counts remain balanced.

Notes:

• Translation files were intentionally not modified.
• This is a focused release-note addition and does not claim the broader release-notes issue is complete.

[Reqrefusion]

conflicts