Update figure link tag

[sjspielman]

From #33 (comment), we're going to be adding figure links into legends. We do not have a formal release tag in the scpca-paper-figures repo, so for now we are going to link to main.

This issue tracks updating these links from main to the release tag, once it exists.

[jaclyn-taroni]

@allyhawkins did you do this as part of your edits in #81?

[allyhawkins]

@allyhawkins did you do this as part of your edits in #81?

No, we still need to change the actual link to the figures to point to the release.

[jaclyn-taroni]

I meant to ask this about #48 🤦🏻