[Ipopt] GitHub discussions to replace mailing list

[Stefan Vigerske]

Hi,

GitHub Discussions has been enabled for the Ipopt project: 
https://github.com/coin-or/Ipopt/discussions

Discussions work similar to issues, but are targeted towards the purpose 
of mailing lists. GitHub phrases this as "This a place to connect with 
other members of our community on topics not suited for opening an 
Issue. We hope that you:
- Ask questions you're wondering about.
- Share ideas.
- Engage with other community members.
- Welcome others and are open-minded."

COIN-OR plans to discontinue the mailing lists that are hosted on the 
COIN-OR server in favor of moving everything to GitHub discussions. It 
hasn't been decided yet when the mailing list will be closed.
The mailing list archive (https://list.coin-or.org/pipermail/ipopt/) is 
supposed to be preserved.

A GitHub account will be required to write in discussions.
To be notified about activity in discussions, you can watch the project 
on GitHub: Load https://github.com/coin-or/Ipopt in your web browser, 
click on "Watch" in the top-right corner, click on "Custom", tick 
"Discussions".
At the same place, you can also enable to be notified about releases. 
I'll stop posting Ipopt release notifications to this list.

Best,
Stefan