Update public api GTFS format documentation

[indexjoseph]

These changes update the GTFS static specification from the deprecated documentation at https://developers.google.com/transit/gtfs/reference/ to the current documentation at https://gtfs.org/reference/static/.

See the image below for the deprecated reference page: https://developers.google.com/transit/gtfs/reference/

[jamespfennell]

I don’t think all of the new URLs are quite correct. For example in the PR alerts link to https://gtfs.org/realtime/feed-entities/service-alerts/#service-alerts but probably should link to https://gtfs.org/realtime/reference/#message-alert where the fields are defined. Ideally both links would be present, but I think we need to include the reference links at least.

[jamespfennell]

Forgot to say: thank you for the PR.

[jamespfennell]

Looks like the CI failed because there is a mismatch between the protos and generated files in source control.

For the Docker image there might be a mismatch between your local version of protoc and the one in the docker image.

for the documentation you need to run

go run docs/src/api/api_docs_gen.go

in the repo root to update the docs after changing the protos.

[indexjoseph]

I had to run buf generate to create the api_docs_gen_input.json, and afterwards I was able to run the go docs file. Thanks for the help.

[jamespfennell]

Thanks Joseph! Sorry for the late submit :)

[indexjoseph]

All good!