I think there is an error in the documentation in chapter "Create a new web part project".
"What is your Web part name?" should be "jQuery" and not " jQuery Web Part" otherwise the code samples aren't correct.
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Mainly wrong description here:

Should be src/webparts/jQueryWebPart if the web part name is jQuery Web Part
Sorry, but the error is still in there.

This should be updated to: What is your Web part name?: jQuery

It's fixed, it's just not live on the docs site. The live branch reflects what's currently on the .COM public site. The PR applied the changes to the master branch which will get merged into the live branch. This is usually done on a scheduled basis. The person at Microsoft who usually does this is currently on vacation, so it might take a bit longer as only urgent things will likely get pushed out.
The issue was automatically closed because the person who submitted the PR linked the issue (correctly) to the PR so it was automatically closed when the PR was merged.
Ok, I'm sorry. It was the first time I've reported an issue. :-)
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