Add capability for mathjax equations per instructions here (#126)

https://bookdown.org/yihui/blogdown/templates.html

exampleSite/config.toml

@@ -63,7 +63,9 @@ pluralizeListTitles = false
   highlightjsCDN = "//cdn.bootcss.com"
   highlightjsLang = ["r", "yaml", "css"]
   highlightjsTheme = "github"
-
+  MathJaxCDN = "//cdn.bootcss.com"
+  MathJaxVersion = "2.7.1"
+
 # Disqus will take priority over Staticman (github.com/eduardoboucas/staticman)
 # due to its ease of use. Feel free to check out both and decide what you would
 # prefer to use. See Staticman.yml for additional settings.
@@ -187,6 +189,6 @@ pluralizeListTitles = false
   vine             = ""
   googlescholar    = ""
   orcid            = ""
-  researchgate     = "example"    
+  researchgate     = "example"
   # Email
   email            = "example"

layouts/partials/footer.html

@@ -41,5 +41,6 @@
 
     <!-- This is called by default since this theme uses highlight.js -->
     <script>hljs.initHighlightingOnLoad();</script>
+      {{ partial "footer_mathjax" . }}
   </body>
 </html>

layouts/partials/footer_mathjax.html

@@ -0,0 +1,5 @@
+<script src="//yihui.name/js/math-code.js"></script>
+<script async
+src="{{ .Site.Params.MathJaxCDN | default "//cdn.bootcss.com"}}/mathjax/{{ .Site.Params.MathJaxVersion | default "2.7.1" }}/MathJax.js?config=TeX-MML-AM_CHTML">
+</script>
+