Accept boolean as well as string (#119)

Martin Kiesel

20.39.2018 e33d2ec88aebdb39838fd7b419041ddfb702db1a

 layouts/partials/posts/math.html

@@ -1,4 +1,4 @@
{{- if eq .Params.math "true" -}}
{{- if .Params.math -}}
  <script type="text/javascript" async
    src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.4/MathJax.js?config=TeX-AMS-MML_HTMLorMML-full">
    MathJax.Hub.Config({