[EPIC] Add "Running and Debugging app" page

[dhmlau]

Suggestion

In LB3 docs, there's Running and debugging apps page. A similar version for LB4 would be useful.

Acceptance Criteria

• Running and debugging apps
  • setting debug strings
    • The connector ones would be the same. For others, not every debug strings would be the same. e.g. strong-remoting
  • error handling
    • instead of using strong-error-handler, we need to document how to configure http response for errors and how to report error from controller.
    • Note: there are other error handling pages in LB4, we might need to see where is the best place to have this info.

[agnes512]

closing as done