Fix broken links

Author: dksimpson

articles/azure-maps/elevation-data-services.md

@@ -363,7 +363,7 @@ http://localhost:7071/api/tileserver?zoom={z}&x={x}&y={y}
 [QGIS]: https://www.qgis.org/en/site/forusers/download.html
 [rio-rgbify]: https://pypi.org/project/rio-rgbify/
 [PostgreSQL]: https://www.postgresql.org/download/
-[PostGIS]: https://postgis.net/install/
+[PostGIS]: https://postgis.net/documentation/getting_started/#learn-about-spatial-sql
 [Azure Maps Web SDK]: about-azure-maps.md#web-sdk
 [Create Contour line vector tiles and RGB-encoded DEM tiles]: #create-contour-line-vector-tiles-and-rgb-encoded-dem-tiles
 [Create Contour line vector tile service using Azure Function and PostgreSQL]: #create-contour-line-vector-tile-service-using-azure-function-and-postgresql