Update index.rst
Update index.rst

Fix underline under longer version guide name or else throws Sphinx warning
ekoi/DANS-DVN-4.6.1,JayanthyChengan/dataverse,jacksonokuhn/dataverse,JayanthyChengan/dataverse,ekoi/DANS-DVN-4.6.1,jacksonokuhn/dataverse,jacksonokuhn/dataverse,jacksonokuhn/dataverse,JayanthyChengan/dataverse,ekoi/DANS-DVN-4.6.1,JayanthyChengan/dataverse,ekoi/DANS-DVN-4.6.1,JayanthyChengan/dataverse,ekoi/DANS-DVN-4.6.1,JayanthyChengan/dataverse,jacksonokuhn/dataverse,ekoi/DANS-DVN-4.6.1,ekoi/DANS-DVN-4.6.1,jacksonokuhn/dataverse,jacksonokuhn/dataverse,JayanthyChengan/dataverse,ekoi/DANS-DVN-4.6.1,JayanthyChengan/dataverse,jacksonokuhn/dataverse