add link to `discuss.{...}` to the homepage header?

[lucascolley]

Please describe the new feature.

Does it make sense to link to https://discuss.scientific-python.org/ alongside Home, Blog, and Learn at the top of https://scientific-python.org?

Add any other context about the new feature here, screenshots, etc.

No response

[jarrodmillman]

There are a few websites that will need updating and I want to roll out a theme update first. I am busy working on a couple of grant proposals, so it may be a week or two before I get to this.