docs(ngMock::$log): improve the `$log.*.logs` descriptions
docs(ngMock::$log): improve the `$log.*.logs` descriptions

Because ngDoc generation only takes the last segment of a property name,
each $log.[error|warn|log...].logs property has the same name and is
confusing in the docs.
This commit helps this by adding a link to the $log.* method and also an
appropriate usage example.

ammula88/angular.js,ammula88/angular.js,ammula88/angular.js,ammula88/angular.js,ammula88/angular.js