Add the five docs.plus extensions to the awesome-tiptap list

[HMarzban]

The Tiptap community keeps a curated list at ueberdosis/awesome-tiptap. It is run by ueberdosis, the company that builds Tiptap, and the Tiptap docs send readers to it.

docs.plus is not on that list. A search of its README.md for docs.plus, docs-plus, and docsplus returns nothing.

We publish five Tiptap 3 extensions, so we belong in two of its sections.

What to do

Open one pull request against ueberdosis/awesome-tiptap that edits README.md on the main branch.

Add five lines under ## Community extensions, one per package. Keep the section's alphabetical order. The format carries no description:

- [@docs.plus/extension-hyperlink](https://www.npmjs.com/package/@docs.plus/extension-hyperlink) by [@docs-plus](https://github.com/docs-plus)

The five packages are extension-hyperlink, extension-hypermultimedia, extension-indent, extension-inline-code, and extension-placeholder.

Then add one line under ## Open source projects using Tiptap. That section does take a description, and docs.plus sorts between Docmost and Doist Typist:

- [docs.plus](https://github.com/docs-plus/docs.plus) - Real-time collaborative document editor with per-heading chat by [@docs-plus](https://github.com/docs-plus)

Things that are already checked

• The repo has no CONTRIBUTING.md and no stated inclusion rule. A plain pull request is the process.
• There is no minimum star count.
• Monorepo subpaths are accepted. Three existing entries point inside a packages/ directory.
• npm package links are accepted. Several existing entries use them.
• The list is active. Twelve pull requests from twelve different outside authors merged recently.

Done when

The pull request is merged, and docs.plus appears in both sections.