Support other types of volumes

[yamalight]

Currently, exoframe-server only allows using volume type volumes [1].
There needs to be a way to specify other types (e.g. users might want to use bind type with docker socket for other docker-bound app like portainer).

[1] https://github.com/exoframejs/exoframe-server/blob/5725c91c4ba759011cd17c6d11a3dc420c632f89/src/docker/start.js#L351

[yamalight]

Done. Can now be specified via third parameter after :, e.g. "/tmp:/tmp:bind". To be documented.