Update-package-from-gitlab-repo.md

+The parameters might not all be required but it works for upgrading a package from the gitlab server:
+```
+pip install scikit-build
+pip install --no-cache-dir --no-deps --upgrade --no-build-isolation -i https://gitlab.dune-project.org/api/v4/projects/812/packages/pypi/simple dune-fem
+```
+I've used this now to pass on a patch to a user.
+
+Please add if you have another suggestion.
+
+I was wondering if we should add a command, i.e., to `dune._mmain__` that allows to do such an update, for example
+```
+  python -m dune update -i gitlab fem
+```
+that does the same?
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