docs(popover): correct default trigger

Closes #5564
Closes #5566

Author: KyleUpchurch

Diff for: src/popover/docs/readme.md

@@ -71,7 +71,7 @@ All these settings are available for the three types of popovers.
    A string to display as a fancy title.
 
 * `popover-trigger`
-  _(Default: `mouseenter`)_ -
+  _(Default: `click`)_ -
   What should trigger a show of the popover? Supports a space separated list of event names (see below).
 
 **Note:** To configure the tooltips, you need to do it on `$uibTooltipProvider` (also see below).