activitypub: implement /api/v1/activitypub/user/{username} (#14186)

Return informations regarding a Person (as defined in ActivityStreams
https://www.w3.org/TR/activitystreams-vocabulary/#dfn-person).

Refs: https://github.com/go-gitea/gitea/issues/14186

Signed-off-by: Loïc Dachary <loic@dachary.org>

routers/api/v1/swagger/activitypub.go

@@ -0,0 +1,16 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package swagger
+
+import (
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// ActivityPub
+// swagger:response ActivityPub
+type swaggerResponseActivityPub struct {
+	// in:body
+	Body api.ActivityPub `json:"body"`
+}