update doc

CHANGELOG.md

@@ -8,6 +8,7 @@ CHANGELOG
 * configure licence https://github.com/Psycojoker/prosopopee#licence in footer by beudbeud
 * possibility to use a range for the full picture date https://github.com/Psycojoker/prosopopee#full-screen-picture-with-or-without-text-on-it by beudbeud
 * Update material theme by beudbeud
+* social share https://github.com/Psycojoker/prosopopee#share by beudbeud 
 
 0.2 (2016-02-23)
 ----------------

README.md

@@ -143,6 +143,16 @@ licence:
    url: "http://www.wtfpl.net/txt/copying/"
 ```
 
+##### Share
+
+If you want enable the share content on social network, add key in **root** settings.yaml. For example: 
+By defaut you can share on facebook, twitter, pinterest, google+.
+
+```yaml
+share: True
+url: "http://prosopopee.com/"
+```
+
 ### Gallery settings.yaml
 
 This settings.yaml will describe: