SHA1 sums are incorrect

[m-nez]

Size and SHA1 Sum fields are flipped in https://github.com/gwtproject/gwt-site/blob/main/src/main/markdown/versions.md (https://www.gwtproject.org/versions.html). Also the SHA1 sum is incorrect for Version 2.12.1 (possibly also for other versions). The sum looks like the md5sum with 8 prepended.

[niloc132]

Thanks, 2.10.1 and above need to be updated to flip the values in the tables to be consistent with the older versions.

The md5sum issue is weird, but definitely my fault in copying those values (and my bash history clearly shows I ran md5sum when I should have run sha1sum).

@zbynek looks like we also have an issue with the download links themselves - I suspect changing our markdown engine broke those (markdown embedded in html), can you look into that?