What would be the best way to generate custom maps for use with an algorithm like Dijstra's or A*? I have seen some methods using various game level editors to output to a grid, but is there an easy way to draw custom maps, such as indoors locations, and create your node map with additional JSON data visually?
You can try one of the Quickstart guides on that page. Just type in "San Francisco" in the search bar on the map on this page: https://overpass-turbo.eu/ and then run your search query (drinking fountains by default). The bounding box should be whatever is in view of the map on the right. Then you can click the Data tab to see exported XML.