suppress unknown mimetype warnings -- colab as specialized output json now

Author: mmcky

lectures/_config.yml

@@ -37,11 +37,11 @@ sphinx:
     # false-positive links
     linkcheck_ignore: ['https://online.stat.psu.edu/stat415/book/export/html/834']
     bibtex_reference_style: author_year
+    suppress_warnings: ["mystnb.unknown_mime_type"]
     nb_mime_priority_overrides: [
        # HTML
        ['html', 'application/vnd.jupyter.widget-view+json', 10],
        ['html', 'application/javascript', 20],
-       ['html', 'application/vnd.colab-display-data+json', 25],
        ['html', 'text/html', 30],
        ['html', 'text/latex', 40],
        ['html', 'image/svg+xml', 50],