Add the layer_id to the layer description

[nickpeihl]

The Tile Layers and Vector Layers in the landing page are only referred to by their human readable names. We should also find a way to include their respective layer_ids (ex. road_map, world_countries) in the page. This will help users who are creating maps in Kibana Vega visualizations where the layer_ids need to be known.

[nreese]

Thanks. This will be a great addition. I have always found it confusing that there is not tile layer details like the details listed for files.

It would be great if the default EMS page redirected to a tile layer instead of world countries.

[nreese]

elastic/kibana#88440 allows users to specify the EMS baselayer id in mapStyle parameter. The EMS layer ids are hard coded in the docs at docs/user/dashboard/vega-reference.asciidoc. These docs need to updated to link to EMS once EMS provides a way to view the ids of the available base layers.