Update src/plot_api/plot_config.js

Co-authored-by: Alex Johnson <johnson.alex.c@gmail.com>

Author: archmoj

src/plot_api/plot_config.js

@@ -25,7 +25,10 @@ var configAttributes = {
     typesetMath: {
         valType: 'boolean',
         dflt: true,
-        description: 'Determines whether the math should be typeset or not.'
+        description: [
+            'Determines whether math should be typeset or not,',
+            'when MathJax (either v2 or v3) is present on the page.'
+        ].join(' ')
     },
 
     plotlyServerURL: {