DOC: Add SSLCertVerificationError warning message for documentation build fail

Author: jeffersbaxter

doc/source/development/contributing_documentation.rst

@@ -157,6 +157,13 @@ If you want to do a full clean build, do::
     python make.py clean
     python make.py html
 
+.. error::
+  The command ``python make.py html`` requires SSL verification.
+  If the command exits with an error status.
+  Try running the command ``python make.py html --num-jobs=1``.
+  If the terminal output reports a SSLCertVerificationError,
+  update your local SSL. Then, rerun ``python make.py html``.
+
 You can tell ``make.py`` to compile only a single section of the docs, greatly
 reducing the turn-around time for checking your changes.