GitHub: link to a faster landing page in GerritHub
The dashboards have changed in Gerrit 3.4 which got deployed to
GerritHub earlier today. Now there's no pagination and no is:mergeable
operator. Let's just link to a (paginated) list of all open changes,
that's probably better value for now.
# Thanks for contributing to GNPy
If it isn't much trouble, please send your contribution as patches to our Gerrit.
-Here's [how to submit patches](https://review.gerrithub.io/Documentation/intro-gerrit-walkthrough-github.html), and here's a [list of stuff we are currently working on](https://review.gerrithub.io/p/Telecominfraproject/oopt-gnpy/+/dashboard/main:main).
+Here's [how to submit patches](https://review.gerrithub.io/Documentation/intro-gerrit-walkthrough-github.html), and here's a [list of stuff we are currently working on](https://review.gerrithub.io/q/project:Telecominfraproject/oopt-gnpy+status:open).
Just sign in via your existing GitHub account.
However, if you feel more comfortable with filing GitHub PRs, we can work with that too.
