Clicking the "Creating Plugins" button on the https://www.gatsbyjs.org/ home page in the plugins section (see image) leads to a 404.

Refreshing the page after that triggers the correct(?) redirect.
Additionally, there is at least one more broken link on this page:
https://www.gatsbyjs.org/docs/plugins/
and there could be other cases so maybe global search for the slug to search and replace is a good idea.
We should see the relevant page or be redirected correctly.
We see a 404.
N/A
Could this be something specific to your machine? I'm not able to replicate the issue and the link works as expected for me in both Firefox and Chrome on Windows 10, also fine on my Pixel 2 in Chrome.
Edit: Ignore that, I was clicking on "Using plugins" rather than "Creating Plugins". I do indeed get a 404 when clicking "Creating Plugins".
Hm, don't think it's just me, or then could it be some CDN edge caching issue?
I get consistent 404 when clicking the button on my mac, any browser, incognito or not; also tested on my Pixel 3 chrome incognito and not, either way always 404 on that link (also tested on 4G and WiFi, just to change networks). Would be nice if more people could test.
Apologies, I think I was mislead by the "Using plugins" being white in your screenshot and was testing that instead, updated with my original post as I do in fact experience the same issue as you when clicking "Create Plugin"
I can recreate and have found several more cases of this relatively quickly.
Seems as though the /docs/plugin-authoring/ page does not exist. A refresh redirects to /docs/how-plugins-work/.
Are you taking this one @jumpalottahigh? Else I will put a PR in for it.
@JABedford , please, go for it! I'd absolutely love to help, but I have one too many things on my table at the moment :(. Very happy you are jumping in though! Thank you.
I know that feeling!
EDIT: Just run a global search for the slug and there are 15 cases of this page being directed to. Would be interested to know what happened here @DSchau and how we can resolve this? Presumably, this was a page at some point.
I guess for now I will just redirect them to the "How Plugins Work" page. Probably better than a broken link?
This has been quiet for a while and I had some time to put together #12736 , hope you don't mind @JABedford .
No, absolutely not. I just never had the time to look into it properly.