Update index.markdown
Update index.markdown

remove extraneous comma
rbrw/puppetdb,puppetlabs/puppetdb,rbrw/puppetdb,rbrw/puppetdb,rbrw/puppetdb,puppetlabs/puppetdb,rbrw/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb