Update the document about cannorin's extern search

[naqtn]

(This is not a bug report actually. But I thought this is a better place to request.)

The document mentions "cannorin's extern search" https://udonsharp.docs.vrchat.com/community-resources#cannorins-extern-search as This is fairly out of date at this point. Recently, they made an automated update procedure, which reflects the latest SDK https://twitter.com/cannorin_vrc/status/1642001383326121988 . So would you rewrite that notes?