BUG: Fix the doc-generation of examples
BUG: Fix the doc-generation of examples

Doc generation for examples was failing because it was trying to make
docs from directories containing the automatically-downloaded data of the
examples. The solution is simply to skip these directories

Eric89GXL/sphinx-gallery,sphinx-gallery/sphinx-gallery,Titan-C/sphinx-gallery,Titan-C/sphinx-gallery,lesteve/sphinx-gallery,sphinx-gallery/sphinx-gallery,lesteve/sphinx-gallery,Eric89GXL/sphinx-gallery