Add read-only note for development

docs/more/development.md

@@ -51,6 +51,7 @@ To ensure cohesiveness of various widgets, the following should be used as a gui
 
 - Please only submit widgets that have been requested and have at least 10 'up-votes'. The purpose of this requirement is to avoid the addition (and maintenance) of service widgets that might only benefit a small number of users.
 - Widgets should be only one row of blocks
-- Widgets should be no more than 4 blocks wide
+- Widgets should be no more than 4 blocks wide and generally conform to the styling / design choices of other widgets
 - Minimize the number of API calls
 - Avoid the use of custom proxy unless absolutely necessary
+- Widgets should be 'read-only', as in they should not make write changes using the relevant tool's API. Homepage widgets are designed to surface information, not to be a (usually worse) replacement for the tool itself.