Add Nextdoor logo to social logos and social icons block.

[ritterml]

Nextdoor is a popular network website used by many neighborhood groups and local businesses in the U.S.

Adding this icon to the core blocks will be beneficial to the community.

See Nextdoor branding guide at ​https://about.nextdoor.com/nextdoor-brand-use-guidelines/

[jorbin]

This feels like plugin territory to me and if that proves popular, it should be reconsidered. I would suggest this is closed as maybelater.

[ritterml]

I beg to differ. To close would be premature.

More helpful would be to point to the triage process for adding and icons to the project.

Granted, one _can_ develop and distrubte a (block variation)​https://developer.wordpress.org/block-editor/reference-guides/block-api/block-variations/, but a process to incorporate such feedback is helpful.