DOC: separate section with experimental features in 1.0.0 whatsnew
Just a thought I had, to put the experimental features (pd.NA, string, boolean dtypes) in a separate section, better highlighting that those are experimental. 

Since @TomAugspurger basically wants to release now, this is certainly not a blocker :)
Would maybe put the "Experimental New Features" before the "Other Features", but +1 otherwise. Doc build finished. Merging. @Meeseeksdev backport to 1.0.x Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

```
$ git checkout 1.0.x
$ git pull
```

2. Cherry pick the first parent branch of the this PR on top of the older branch:
```
$ git cherry-pick -m1 eda68cfcda90efdc9c11c1a77094eb0f13a8b1b4
```

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

```
$ git commit -am 'Backport PR #31429: DOC: separate section with experimental features in 1.0.0 whatsnew'
```

4. Push to a named branch :

```
git push YOURFORK 1.0.x:auto-backport-of-pr-31429-on-1.0.x
```

5. Create a PR against branch 1.0.x, I would have named this PR:

> "Backport PR #31429 on branch 1.0.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to [suggest an improvement](https://github.com/MeeseeksBox/MeeseeksDev).
                 Handling the backport. Not sure why it wouldn't be clean.