try mathjax in to-pdf

Author: briantoby

MDhelp/mkdocs.yml_pdf

@@ -1,7 +1,7 @@
 site_name: GSAS-II Help
 
 nav:
-#  - Contents: index.md
+  - Contents: index.md
   - Getting started: preface.md
   - GUI components: applicationwindow.md
   - Main menu: mainmenu.md
@@ -66,11 +66,11 @@ plugins:
       copyright: From https://advancedphotonsource.github.io/GSAS-II-tutorials/help/
       #back_cover: true
       output_path: GSASII-help.pdf
-#      exclude_pages:
+      exclude_pages:
 #        - Contents
-#        - index.md
-#      render_js: true
-#      headless_chrome_path: /usr/bin/chromium-browser
+        - index.md
+      render_js: true
+      headless_chrome_path: /usr/bin/chromium-browser
 
   - i18n:
       docs_structure: suffix