text: Title: Process: Make warning about processes hanging if output buffers get full more visible
  Body: Related to #3661,
  
  Before finding the related issue above, my binary hung when using the `RUN PROCESS`. It has consumed a lot of my time investigating whether the robot test has found a bug or not. I found out that it is a limitation or weird behavior on RF based on the related issue. It could really help other developers to note this limitation, to avoid misunderstanding the test, and to avoid unnecessary investigation. Thank you in advance.
  
  RobotFramework Version: 6.1.1
  Actions to resolve the issue:
  - [ ] Add this limitation or behavior in the Process Library Documentation
  - [ ] Fix the bug ( if possible )