docs: Merge pull request #1877 from poldracklab/docs/confounds_desc_acessibility

DOC: Improving accessibility of confounds description

Author: oesteban

docs/links.rst

@@ -17,4 +17,5 @@
 .. _`Docker installation`: https://docs.docker.com/install/
 .. _`Docker Hub`: https://hub.docker.com/r/poldracklab/fmriprep/tags
 .. _Singularity: https://github.com/singularityware/singularity
-.. _TACC: https://www.tacc.utexas.edu/
+..  _SPM: https://www.fil.ion.ucl.ac.uk/spm/software/spm12/
+.. _TACC: https://www.tacc.utexas.edu/