This commit adds API documentation for the new upload
endpoints related to direct + multipart external uploads.
Also included is a rake task which watches the files in
the spec/requests/api directory and calls a script file
(spec/regenerate_swagger_docs) whenever one changes. This
script runs rake rswag:specs:swaggerize and then copies
the openapi.yml file over to the discourse_api_docs repo
directory, and hits a script there to convert the YML to
JSON so the API docs are refreshed while the server is
still running. This makes the loop of making a doc change
and seeing it in the local server much faster.
The rake task is rake autospec:swagger