New Issue: Adjust generated documentation for deprecated symbols

17948, "lydia-duncan", "Adjust generated documentation for deprecated symbols", "2021-06-18T18:50:33Z"

It would be handy for deprecated symbols to automatically indicate that they are deprecated in chpldoc's output. I was thinking something along the lines of adding a .. warning:: with the provided error message.

Users might want to explicitly link to the new symbol to use if there is one. It might not be too hard to detect if there is already a .. warning with deprecation mentioned in some form in the documentation and suppress the generated one if so (I think it would be much more difficult to adjust the generated message to detect if there is an alternative symbol listed and link to that, so wouldn't expect to pursue that path)