Docs: improve doc on migrating from self-hosted GitLab to GitLab.com
- From this thread on Slack
- This is what we have: https://docs.gitlab.com/ee/user/project/import/#migrating-from-self-hosted-gitlab-to-gitlab-com
- We should make a guide similar to https://docs.gitlab.com/ee/user/project/import/gitlab_com.html, linking https://docs.gitlab.com/ee/user/project/import/repo_by_url.html.
cc/ @axil @mikelewis
Edited by Marcia Ramos