FR translation: add file to translate

Author: nfabredev

docs/playground/fr/3-7/Fixits/Const to let.ts

@@ -0,0 +1,12 @@
+//// { compiler: {  }, order: 1 }
+
+// New to 3.7 is the ability to quickly convert
+// a const variable to a let when the value
+// has been re-assigned.
+
+// You can try this by highlighting the below error
+// and choosing to run the quick-fix.
+
+const displayName = "Andrew";
+
+displayName = "Andrea";