Abbreviate landmark names in braille (PR #6813)
The names of "landmarks" are abbreviated in Braille
Fixes #3975
Abbreviations:
- "landmark": "lmk"
- "banner": "bnnr"
- "complementary": "comp"
- "contentinfo": "cinf"
- "main": "main"
- "navigation": "nav"
- "search": "srch"
- "form": "frm"
- "region": "rgn"
Example: "navigation landmark" becomes "lmk nav"