[gravatar] Add addon config

- Update mentions to .htconfig.php

gravatar/config/gravatar.ini.php

@@ -0,0 +1,28 @@
+<?php return <<<INI
+
+; Warning: Don't change this file! It only holds the default config values for this addon.
+; Instead overwrite these config values in config/local.ini.php in your Friendica directory
+
+[gravatar]
+; default_avatar (String)
+; If no avatar was found for an email Gravatar can create some pseudo-random generated avatars based on an email hash.
+; You can choose between these presets:
+; - gravatar : default static Gravatar logo
+; - mm       : (mystery-man) a static image
+; - identicon: a generated geometric pattern based on email hash
+; - monsterid: a generated 'monster' with different colors, faces, etc. based on email hash
+; - wavatar  : faces with different features and backgrounds based on email hash
+; - retro    : 8-bit arcade-styled pixelated faces based on email hash
+default_avatar = gravatar
+
+; rating (String)
+; Gravatar lets users self-rate their images to be used at appropriate audiences.
+; Choose which are appropriate for your friendica site:
+; - g : suitable for display on all wesites with any audience type
+; - pg: may contain rude gestures, provocatively dressed individuals, the lesser swear words, or mild violence
+; - r : may contain such things as harsh profanity, intense violence, nudity, or hard drug use
+; - x : may contain hardcore sexual imagery or extremely disurbing violence
+rating = g
+
+INI;
+//Keep this line