Update readme and upgrade with the url for the new forge

Description

Update readme and upgrade with the url for the new forge

Steps to Reproduce

1. rgrep forge.fusiondirectory.org

Expected behavior:

see https://gitlab.fusiondirectory.org/

Actual behavior:

we see https://forge.fusiondirectory.org/

Reproduces how often:

100%

Additional Information

created branch 5791-update-readme-and-upgrade-with-the-url-for-the-new-forge

By bmortier on 2018-03-17T14:31:06 (imported from GitLab)

mentioned in merge request !164

By bmortier on 2018-03-17T14:31:07 (imported from GitLab)

closed via commit baa34686

By bmortier on 2018-03-17T14:55:23 (imported from GitLab)

closed via merge request !164

By bmortier on 2018-03-17T14:55:23 (imported from GitLab)

mentioned in commit 2b7c26b0

By bmortier on 2018-03-17T14:55:50 (imported from GitLab)

mentioned in merge request !165

By bmortier on 2018-03-17T14:55:50 (imported from GitLab)

mentioned in commit baa34686

By bmortier on 2018-03-20T15:30:05 (imported from GitLab)

added user-manual label

By bmortier on 2018-03-23T12:54:23 (imported from GitLab)