[DOC release] Update get helper documentation, fixes #13080

[irminsul]

No description provided.

[mixonic]

I'm not wild about advertising onclick={{action in our documentation.

I think this is just hiding a bug. <button {{action (mut foo)}}> seems reasonable to support to me.

[irminsul]

I agree, <button onclick={{action (mut foo) 'bar'}}> isn't very nice. I've just stumbled across the two broken examples in the documentation and thought they should be fixed.

[locks]

For what is worth, <button {{action (action (mut foo))}}> works and I believe it's even somewhere in the Guides?

[homu]

☔ The latest upstream changes (presumably #14163) made this pull request unmergeable. Please resolve the merge conflicts.