Added first (invaluable) resource for JavaScript reference

Author: jonasbn

README.md

@@ -303,6 +303,7 @@
 - [Use a styleguide](javascript/use_a_style_guide.md)
 - [Beware of eval](javascript/beware_of_eval.md)
 - [Default Parameters for Functions](javascript/function_default_parameters.md)
+- [Learn JavaScript](javascript/learn_javascript.md)
 
 <a id="jira"></a>
 ### Jira

javascript/learn_javascript.md

@@ -0,0 +1,7 @@
+# Learn JavaScript
+
+_TODO_
+
+## Resources
+
+- [Mozilla Developer Network (MDN)](https://developer.mozilla.org/en-US/docs/Web/JavaScript)