Added JAAG community tool to documentation

[pavithra-rvce]

This PR adds a short documentation section for the JAAG community GUI tool,
which helps generate AlphaFold 3 JSON input files with glycan integration.

type of change : Documentation-only change.

Related to issue #537.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[pavithra-rvce]

I’ve opened a PR adding JAAG to the AlphaFold3 documentation:

#583

[Augustin-Zidek]

Done slightly differently in 3e2bc0c, many thanks for JAAG and the PR.

[pavithra-rvce]

Thanks a lot for incorporating this and for the review — much appreciated!