docs: add screenshot to README and appinfo

README.md

@@ -4,3 +4,15 @@ A plugin to add more pride flags to your Nextcloud!
 
 The app supports setting pride-flags for various UI elements of your
 Nextcloud per-user, in the user settings section.
+
+![Nextcloud showing various elements in pan, trans, lesbian and rainbow pride flags](img/pride_flag_variants.png)
+
+## Currently supported pride flags
+
+- 'rainbow' pride flag
+- trans pride flag
+- pansexual pride flag
+- non-binary pride flag
+- bisexual pride flag
+- asexual pride flag
+- lesbian pride flag