Invert symlink and content for the README file

GitLab will display the content of the README file when browsing the
repository. But in case the file is a symlink, it will display the
path pointed by the symlink. There is a 6 year old issue about this:
https://gitlab.com/gitlab-org/gitlab/-/issues/15093

We can workaround the issue by having the content at the root of the
repository and a symlink to this file in the `docs/` directory.

Tested in swh/devel/swh-py-template!27

README.rst

-docs/README.rst
\ No newline at end of file

README.rst

+Software Heritage Filesystem (SwhFS)
+====================================
+
+User-space POSIX filesystem to browse the `Software Heritage
+<https://www.softwareheritage.org/>`_ `archive
+<https://archive.softwareheritage.org/>`_, as if it were locally available.
+
+Built using the `FUSE <https://github.com/libfuse/libfuse>`_ framework.
+
+
+Demo
+----
+
+A live demo of SwhFS in action is available as a `screencast
+<https://www.youtube.com/watch?v=2L4ANVlICaE>`_.
+
+
+Bibliography
+------------
+
+In addition to accompanying technical documentation, SwhFS is also described in
+the following scientific paper. If you use SwhFS for your scientific results,
+please acknowledge it by citing the paper as follows:
+
+.. note::
+
+  Thibault Allançon, Antoine Pietri, Stefano Zacchiroli. `The Software Heritage
+  Filesystem (SwhFS): Integrating Source Code Archival with Development
+  <https://arxiv.org/pdf/2102.06390.pdf>`_. In proceedings of `ICSE 2021
+  <https://conf.researchr.org/home/icse-2021>`_: The 43rd International
+  Conference on Software Engineering, May 2021, Madrid, Spain. IEEE 2021.
+
+  Links: `preprint <https://arxiv.org/pdf/2102.06390.pdf>`_, `bibtex
+  <https://upsilon.cc/~zack/research/publications/saner-2020-swh-graph.bib>`_.

docs/README.rst

-Software Heritage Filesystem (SwhFS)
-====================================
-
-User-space POSIX filesystem to browse the `Software Heritage
-<https://www.softwareheritage.org/>`_ `archive
-<https://archive.softwareheritage.org/>`_, as if it were locally available.
-
-Built using the `FUSE <https://github.com/libfuse/libfuse>`_ framework.
-
-
-Demo
-----
-
-A live demo of SwhFS in action is available as a `screencast
-<https://www.youtube.com/watch?v=2L4ANVlICaE>`_.
-
-
-Bibliography
-------------
-
-In addition to accompanying technical documentation, SwhFS is also described in
-the following scientific paper. If you use SwhFS for your scientific results,
-please acknowledge it by citing the paper as follows:
-
-.. note::
-
-  Thibault Allançon, Antoine Pietri, Stefano Zacchiroli. `The Software Heritage
-  Filesystem (SwhFS): Integrating Source Code Archival with Development
-  <https://arxiv.org/pdf/2102.06390.pdf>`_. In proceedings of `ICSE 2021
-  <https://conf.researchr.org/home/icse-2021>`_: The 43rd International
-  Conference on Software Engineering, May 2021, Madrid, Spain. IEEE 2021.
-
-  Links: `preprint <https://arxiv.org/pdf/2102.06390.pdf>`_, `bibtex
-  <https://upsilon.cc/~zack/research/publications/saner-2020-swh-graph.bib>`_.

docs/README.rst

+../README.rst
\ No newline at end of file