chore: add linter config

.jshintrc

@@ -0,0 +1,22 @@
+{
+    "browser": true,
+    "node": true,
+    "esversion": 11,
+    "curly": true,
+    "sub": true,
+    "bitwise": true,
+    "eqeqeq": true,
+    "forin": true,
+    "freeze": true,
+    "immed": true,
+    "latedef": "nofunc",
+    "nonbsp": true,
+    "nonew": true,
+    "plusplus": true,
+    "undef": true,
+    "unused": "vars",
+    "strict": true,
+    "maxdepth": 3,
+    "maxstatements": 100,
+    "maxcomplexity": 10
+}