Provide a link to the most recent documentation

[sprintersb]

In https://avrdudes.github.io/avr-libc/ there is a link to the "Most recent HTML online" documentation.

However, the link is to v2.2.0 documentation, which is the most recent documentation technically, but when you use that link, e.g. in the GCC documentation, then it will still point to v2.2.0 even when v2.3.0 or v3 will be released.

Maybe it's possible to provide something like https://avrdudes.github.io/avr-libc/avr-libc-user-manual/index.html that "magically" points to the most recent version of the documentation.