Disclaimer about GLU licence

[anders-kolstad]

All new indicators on ecRxiv will automatiaclly get the GLY 3.0 licence. We should inform authors of this, perhaps somewhere in the author intructions, or maybe we can have a kind of popup message when you add a new PR?

[anders-kolstad]

We can have the option of manually adding a callout with a different license if the authors want.