fix missing newline at end of installation.rst

Author: namiroues

doc/source/installation.rst

@@ -291,4 +291,4 @@ This installation does not download all the datasets; instead, the datasets are
 .. _pyproject.toml file: https://github.com/MDAnalysis/mdanalysis/blob/35d9d2e3ab08e7e6741b57fe02a7215fe3b91a6c/package/pyproject.toml#L69
 .. _GCC documentation on -march: https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html
 .. _-mcpu: https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html
-.. _Anaconda installer: https://docs.anaconda.com/free/anaconda/install/
+.. _Anaconda installer: https://docs.anaconda.com/free/anaconda/install/