Re-introduce minimal JSHint config

When JSHint is globally activated in people's editors and IDEs, it's
nice to not have it fail, because the rules are different.

Author: raucao

.jshintrc

@@ -0,0 +1,7 @@
+{
+  "esversion": 6,
+  "node": true,
+  "browser": true,
+  "laxbreak": true,
+  "sub": true
+}