Add railroad crossing API

[aa-ko]

Hi,

I recently tried to find an API to query the current status of rail crossings in Germany, but instead stumbled upon this repository. I believe that there is a use-case for an API like this, for example when trying to estimate travel time by car in a navigation app.
Even though this is probably not what you had in mind here, I still think that it fits the repo's theme in general. This data can only be supplied by the operator of the railroad network and has the potential to be very useful for anyone crossing railroads.

I think a railroad crossing can be considered a "place" and a non-functional railroad crossing might also be considered as a "failure". Possible use-cases would include the integration into existing navigation apps.

There seems to be an API for railroad crossings in Switzerland, but this data is pretty much static (updated once a week) and does not include live status data, which is what I am looking for.

Let me know what you think, I'll gladly open a PR and add these ideas to the repo.

[jschirrmacher]

Railroad crossings sounds very much like a "place" with coordinates to me.
I would be happy to review a PR from you and revive this repo again.