I'd like to get some inspiration, could be favorite developer docs, but also resources on how to make them great.
Examples:
Stripe (https://stripe.com/docs): probably the canonical example for dev docs, well written, well structured, sweet spot between code examples and explanatory text (e.g. https://stripe.com/docs/billing/quickstart).
Tailscale (https://tailscale.com/kb/): well written, well structured, lots of how-to guides.
Docusaurus showcase (https://docusaurus.io/showcase): aggregation of docs, some of them are great, some are not. All of them are open source so it's a useful resource for inspiration.
Also, not a doc itself but a great tool to build docs: https://codehike.org/
Northflank API docs: https://northflank.com/docs/v1/api/introduction Very hands-on and easy to search.
The Linux kernel however is by far my favourite because of the in-depth design documents in-tree in easy to read plain-text format.
It's easy to find things, clearly written, and usually answer any questions I have about how to use a particular standard library function.
I really appreciate the code samples, which are present all over the documentation.