Add roadmap to hook help

This is looking great! I really like the plan to provide the roadmap on the module's help page. I'm going to try to work this idea into some other modules.

There are a few minor coding standards issues in the patch.

1. +++ b/admin_status.module
   @@ -8,7 +8,7 @@
   +function admin_status_help($route_name) { ¶
   

   There is an extra trailing space at the end of this line causing it to not meet the Drupal 8 coding standard: "Lines should have no trailing whitespace at the end."

2. +++ b/admin_status.module
   @@ -20,8 +20,13 @@ function admin_status_help($route_name) {
   -
   

   The deletion of this line breaks the coding standard: "Case breaking statements must be followed by a single blank line".

Interestingly enough, the 2nd code smell is not documented on the Drupal coding standards page. I've submitted a comment on the discuss page with all the details, and asked if it should be included.

Made changes suggested in comment #3

Patch attached with the changes.

Patch applied!

Looks good and I liked the roadmap entry on help.

Patch in #4 applied well on simplytest.me. Think we are good to go!

Thanks :)

Crediting everyone who helped.