Doc: Add alternate text for Qt Location images


Alternate text (alt text) improves the documentation experience for
screen readers and for other accessibility tools.

Task-number: QTBUG-135098
Pick-to: 6.11 6.12
Change-Id: If51dd4ac48cad717f50ccc70e00f2f2c5b345fdc
Reviewed-by: David Boddie <david.boddie@qt.io>
commit7c2ef8ade212964d06ecb7fe08ae63757ba7d83d
parentd3e0c9e3fb0c43b56db1ff3132b1d9085c80d4fe
authorJerome Pasion <jerome.pasion@qt.io>
committerDavid Boddie <david.boddie@qt.io>
commit timeThu, 23 Jul 2026 12:35:54 +0000