Intial file created for TypeScript

Not all content but it's a good start

typescript.html.markdown

@@ -0,0 +1,75 @@
+---
+language: TypeScript
+contributors:
+    - ["Philippe Vlérick", "https://github.com/pvlerick"]]
+---
+
+TypeScript is a language that aims at easing development of large scale applications written in JavaScript.
+TypeScript adds common concepts such as classes, modules, interfaces, generics and (optional) static typing to JavaScript.
+It is a superset of JavaScript: any JavaScript code is valid TypeScript code so it can be added seamlessly to any project.
+TypeScript code compiles down to JavaScript.
+
+This article will focus only on TypeScript added syntax, everything else is plain [JavaScript] (../javascript/).
+
+```ts
+//There are 4 basic types in TypeScript
+var isDone: boolean = false;
+var lines: number = 42;
+var name: string = "Anders";
+
+//However, when it's impossible to know, there is the "Any" type
+var notSure: any = 4;
+notSure = "maybe a string instead";
+notSure = false; // okay, definitely a boolean
+
+//For collections, there are typed arrays and generic arrays
+var list: number[] = [1, 2, 3];
+//Or, using the generic array type
+var list: Array<number> = [1, 2, 3];
+
+//For enumerations
+enum Color {Red, Green, Blue};
+var c: Color = Color.Green;
+
+//Lastly, "void" is used in the special case of a function not returning anything
+function bigHorribleAlert(): void {
+  alert("I'm a little annoying box!");
+}
+
+//Interfaces are structural, anything that has the properties is compliant with the interface.
+//In the bellow example, any object that has a name which is a string and an age which is a number is a Person.
+//This is called "duck typing".
+interface Person {
+  name: string;
+  age: number;
+  
+  //Interfaces also support optional properties
+  phone?: number;
+}
+
+//Interfaces can also describe a function type, to describe a function signature
+interface SearchFunc {
+  (source: string, subString: string): boolean;
+}
+//The type can then be used for functions, and the compiler will be able to check that types are compliants
+//Note that only the parameters' types are important, names are not important.
+var mySearch: SearchFunc;
+mySearch = function(src: string, sub: string) {
+  var result = source.search(subString);
+  if (result == -1) {
+    return false;
+  }
+  else {
+    return true;
+  }
+}
+
+
+```
+
+To test TypeScript's compiler, head to the [Playground] (http://www.typescriptlang.org/Playground).
+
+## Further Reading
+ * [TypeScript Official website] (http://www.typescriptlang.org/)
+ * [TypeScript language specifications (pdf)] (http://go.microsoft.com/fwlink/?LinkId=267238)
+ * [Anders Hejlsberg - Introducing TypeScript on Channel 9] (http://channel9.msdn.com/posts/Anders-Hejlsberg-Introducing-TypeScript)