add Macro syntax for argmax and argmin (#35)

* add Macro syntax for argmax and argmin

* add escape chars

Author: mmcky

lectures/_config.yml

@@ -53,6 +53,11 @@ sphinx:
       og_logo_url: https://assets.quantecon.org/img/qe-og-logo.png
       description: This website presents a set of lectures on quantitative economic modeling, designed and written by Thomas J. Sargent and John Stachurski.
       keywords: Python, QuantEcon, Quantitative Economics, Economics, Sloan, Alfred P. Sloan Foundation, Tom J. Sargent, John Stachurski
+    mathjax_config:
+      TeX:
+        Macros:
+          "argmax" : "arg\\,max"
+          "argmin" : "arg\\,min"
     mathjax_path: https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
     rediraffe_redirects:
       index_toc.md: intro.md