hook_help($route_name, \Drupal\Core\Routing\RouteMatchInterface $route_match)
Provide online user help.
By implementing hook_help(), a module can make documentation available to the user for the module as a whole, or for specific pages. Help for developers should usually be provided via function header comments in the code, or in special API example files.
The page-specific help information provided by this hook appears in the Help block (provided by the core Help module), if the block is displ