Address feedback about wording.

.github/ISSUE_TEMPLATE.md

-We’re closing our issue tracker on GitHub so we can focus on the GitLab.com issue tracker and respond to issues more quickly.
+We’re closing our issue tracker on GitHub so we can focus on the GitLab.com project and respond to issues more quickly.
 
-We encourage you to open an issue on the [GitLab.com issue tracker](https://gitlab.com/gitlab-org/gitlab-ce/issues). You can login on GitLab using your GitHub account if you'd like to contribute an issue.
+We encourage you to open an issue on the [GitLab.com issue tracker](https://gitlab.com/gitlab-org/gitlab-ce/issues). You can log into GitLab.com using your GitHub account.

.github/PULL_REQUEST_TEMPLATE.md

-Thank you for taking the time to contribute back to GitLab! Due to the high number of contributions we get, we’re unable to review requests on GitHub right now.
+Thank you for taking the time to contribute back to GitLab!
 
-We encourage you to open a merge request [on GitLab.com](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests). You can login on GitLab.com using your GitHub account.
+Please open a merge request [on GitLab.com](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests), we look forward to reviewing your contribution! You can log into GitLab.com using your GitHub account.