Funkwhale's Audio support

Create+Audio Activity

{
    "to": [
        "https://channels.tests.funkwhale.audio/federation/actors/compositions/followers"
    ],
    "type": "Create",
    "actor": "https://channels.tests.funkwhale.audio/federation/actors/compositions",
    "object": {
        "id": "https://channels.tests.funkwhale.audio/federation/music/uploads/42342395-0208-4fee-a38d-259a6dae0871",
        "to": "https://www.w3.org/ns/activitystreams#Public",
        "tag": [
            {
                "name": "#funkwhale",
                "type": "Hashtag"
            },
            {
                "name": "#test",
                "type": "Hashtag"
            },
            {
                "name": "#tests",
                "type": "Hashtag"
            }
        ],
        "url": [
            {
                "href": "https://channels.tests.funkwhale.audio/api/v1/listen/3901e5d8-0445-49d5-9711-e096cf32e515/?upload=42342395-0208-4fee-a38d-259a6dae0871&download=false",
                "type": "Link",
                "mimeType": "audio/ogg"
            },
            {
                "href": "https://channels.tests.funkwhale.audio/library/tracks/74",
                "type": "Link",
                "mimeType": "text/html"
            }
        ],
        "name": "Compositions - Test Audio for Pleroma",
        "type": "Audio",
        "content": "<p>This is a test Audio for Pleroma.</p>",
        "summary": "#funkwhale #test #tests",
        "@context": [
            "https://www.w3.org/ns/activitystreams",
            "https://w3id.org/security/v1",
            {
                "manuallyApprovesFollowers": "as:manuallyApprovesFollowers"
            }
        ],
        "mediaType": "text/html",
        "published": "2020-03-11T10:01:52.714918+00:00",
        "attributedTo": "https://channels.tests.funkwhale.audio/federation/actors/compositions"
    },
    "@context": [
        "https://www.w3.org/ns/activitystreams",
        "https://w3id.org/security/v1",
        {
            "manuallyApprovesFollowers": "as:manuallyApprovesFollowers"
        }
    ]
}