Add Gramps Web to Users List

[mahula]

This PR adds Gramps Web to the Users section of the awesome-maplibre list.

What is Gramps Web:
A modern, free & open source web app for collaborative genealogy and family history research. Fully interoperable with the Gramps desktop application, it enables families to browse and collaboratively edit genealogical databases from any web-enabled device.

MapLibre Integration:
Gramps Web migrated from Leaflet to MapLibre GL JS in v25.7.0 (July 2025), bringing significant improvements to their mapping features:

• Vector maps for crisp rendering on any screen
• Smoother zooming and panning
• 3D building visualization in cities
• Interactive location pins with time filters
• Support for image overlays and historical maps (OpenHistoricalMap integration)
• Base map using OpenFreeMap vector tiles based on OpenStreetMap

Changes:

• Added Gramps Web entry to the Users section
• Alphabetically sorted the Users list (A-Z)

Links:

• Website: https://www.grampsweb.org/
• GitHub: https://github.com/gramps-project/gramps-web
• Migration announcement: https://github.com/gramps-project/gramps-web/releases/tag/v25.7.0
• Live demo: https://demo.grampsweb.org/