add mkdocs

docs/widgets/services/photoprism.md

@@ -0,0 +1,14 @@
+---
+title: PhotoPrism
+description: PhotoPrism Widget Configuration
+---
+
+Allowed fields: `["albums", "photos", "videos", "people"]`.
+
+```yaml
+widget:
+    type: photoprism
+    url: http://photoprism.host.or.ip:port
+    username: admin
+    password: password
+```