Add todos

todo.md

+# To-dos
+
+### Main
+
+* User
+* * Registration
+* * Login
+* * Preferences
+* * Review Images/Albums
+* * * incl. delete
+* Admin
+* * Site preferences
+* Upload
+* * Require login
+* View
+* * Individual image
+* * Album
+* * By tag
+* * By user
+
+### API
+
+* Login (POST)
+* Upload image (POST)
+* Create album (POST)
+* Delete image (POST)
+* Delete album (POST)
+* * Orphan images or delete images
+* Fetch image (GET)
+* Fetch album (GET)
+* Fetch tag (GET)
+* Fetch user images (GET)