Add Theming to Docs (#108)

* Add files via upload

* Create theming.rst

* Update index.rst

admin_manual/configuration_server/index.rst

@@ -24,3 +24,4 @@ Nextcloud Server Configuration
    js_css_asset_management_configuration
    automatic_configuration
    oc_server_tuning
+   theming

admin_manual/configuration_server/theming.rst

@@ -0,0 +1,20 @@
+=======
+Theming
+=======
+
+In the administrative settings you can modify the appearance of Nextcloud:
+
+* Name 
+* Web Address 
+* Slogan
+* Color: The color of header bar, checkboxes and folder icon
+* Logo: The logo will appear in the header and on the log in page
+* Log in image: The background image of the log in page
+
+
+.. figure:: ../images/theming.png
+
+
+Log in page   
+
+.. figure:: ../images/theming-log-in-page.png