Document git lfs usage

README.markdown

 git-lfs
 =======
 
-https://docs.gitlab.com/ee/topics/git/lfs/
+Documentation: https://gitlab.phys.ethz.ch/help/topics/git/lfs/index
+
+usage
+-----
+
+Enable **Large File Storage** in: Gitlab > Group > Settings > General > Projects in this group can use Git LFS:
+
+![git lfs settings](img/git-lfs-settings.png "git lfs settings")
+
+Install `git-lfs` (pre-installed on managed Linux workstations):
+
+```bash
+apt install git-lfs
+```
+
+In the git repo clone:
 
 ```bash
 git lfs track "*.png"
 git lfs track "*.jpg"
+git add .gitattributes
+git commit -m 'Store png and jpg in git lfs'
 ```
 
+From now on the lfs tracked files will be uploaded as lfs objects:
+
+```bash
++rda:~/git/test/git-lfs[±]$ git add -A
++rda:~/git/test/git-lfs[±]$ git status
+On branch master
+Your branch is up to date with 'origin/master'.
+
+Changes to be committed:
+  (use "git restore --staged <file>..." to unstage)
+        modified:   README.markdown
+        new file:   img/git-lfs-settings.png
++rda:~/git/test/git-lfs[±]$ git commit -m 'Document git lfs usage'
++rda:~/git/test/git-lfs[+]$ git push
+Locking support detected on remote "origin". Consider enabling it with:
+  $ git config lfs.https://gitlab.phys.ethz.ch/isgphys/git-lfs.git/info/lfs.locksverify true
+Uploading LFS objects: 100% (2/2), 318 KB | 0 B/s, done.
+Enumerating objects: 9, done.
+Counting objects: 100% (9/9), done.
+Delta compression using up to 8 threads
+Compressing objects: 100% (7/7), done.
+Writing objects: 100% (7/7), 843 bytes | 843.00 KiB/s, done.
+Total 7 (delta 0), reused 0 (delta 0), pack-reused 0
+To gitlab.phys.ethz.ch:isgphys/git-lfs.git
+   c65d50b..e73062e  master -> master
+```
+
+users
+-----
+
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