TST: sync translation (one-off) (#649)

* TST: setup action-translation-sync for testing

* TST: translation sync

Author: mmcky

lectures/intro.md

@@ -13,5 +13,7 @@ kernelspec:
 
 This website presents a set of lectures on quantitative economic modeling.
 
+Here is a new section that needs translating.
+
 ```{tableofcontents}
 ```