Enable new encoding for jpg - jpegli

[ssbroad]

github.com/gen2brain/jpegli
Jpegli is an advanced JPEG encoding library that maintains high backward compatibility.
I tested that at the same 90 quality, jpegli saves at least 20% storage space.

[celogeek]

I try mozjpeg too.
the only issue is that it's not out of the box, you have an external dependencies.
it complicate the compilation.

I can make it optional eventually, so you may compile with

go build -tags JPEGLI .

or something like that