Added onCollapsedChange property for DocBlockBase component, which is used by every Doc Block components.
This enables users (story authors) to persist collapsed state somewhere and restore it via defaultCollapsed property, in order to save users' screen estate.
I choose to use onObjectVerb naming style commonly used in DOM, but willing to change if official Storybook code/community has widely used style.
closes #216
Added
onCollapsedChangeproperty forDocBlockBasecomponent, which is used by every Doc Block components. This enables users (story authors) to persist collapsed state somewhere and restore it viadefaultCollapsedproperty, in order to save users' screen estate.I choose to use
onObjectVerbnaming style commonly used in DOM, but willing to change if official Storybook code/community has widely used style.