Add helprunner to show usage information for KRunner plugins
BUG: 433636
The newly added runner adds usage information when typing ? or help.
In the overview, all runners and their first syntax are listed. When selecting one of the results, one gets shown
all the syntaxes for the selected runner. If any of those results are executed, the example query is put in the KRunner search field and the placeholder for the search term is focused.
Needs frameworks/krunner!77 (merged)
After selecting the first result of the above screenshot the UI in KRunner is updated with a query string & the placeholder is selected.
