Added README file.

README.md

+# Miscellaneous utilities for snakemake workflows.
+
+This package contains utilities I use in my snakemake workflows.
+
+
+## Installing
+
+Get the source using `git clone git@gitlab.pasteur.fr:bli/libworkflows.git`,
+`cd` into it and run `python3 -m pip install .`
+
+It might also work directly:
+
+    python3 -m pip install git+ssh://git@gitlab.pasteur.fr/bli/libworkflows.git
+
+
+## Citing
+
+If you use this package, please cite the following paper:
+
+> Barucci et al, 2020 (doi: [10.1038/s41556-020-0462-7](https://doi.org/10.1038/s41556-020-0462-7))
+