Update README.rst (fix syntax for link to CI)

README.rst

@@ -175,7 +175,7 @@ Working example
 ~~~~~~~~~~~~~~~
 
 There is an
-[example](https://github.com/mpsd-computational-science/octopus-with-mpsd-software)
+`example <https://github.com/mpsd-computational-science/octopus-with-mpsd-software>`__
 compilation that shows the complete compilation cycle (including compilation of
 Octopus) using the ``foss2022a-serial`` toolchain.