Improve README.md.

Use code syntax when possible and be consistent with the headers syntax.

README.md

@@ -1,5 +1,4 @@
-FileSaver.js
-============
+# FileSaver.js
 
 FileSaver.js implements the HTML5 W3C `saveAs()` [FileSaver][1] interface in browsers that do
 not natively support it. There is a [FileSaver.js demo][2] that demonstrates saving
@@ -12,8 +11,7 @@ sent to an external server.
 Looking for `canvas.toBlob()` for saving canvases? Check out
 [canvas-toBlob.js](https://github.com/eligrey/canvas-toBlob.js) for a cross-browser implementation.
 
-Supported Browsers
-------------------
+## Supported Browsers
 
 | Browser        | Constructs as | Filenames    | Max Blob Size | Dependencies |
 | -------------- | ------------- | ------------ | ------------- | ------------ |
@@ -29,8 +27,11 @@ Supported Browsers
 
 Feature detection is possible:
 
-    try { var isFileSaverSupported = !!new Blob(); } catch(e){}
-
+```js
+try {
+    var isFileSaverSupported = !!new Blob();
+} catch (e) {}
+```
 
 ### IE < 10
 
@@ -44,29 +45,33 @@ Blobs may be opened instead of saved sometimes—you may have to direct your Saf
 press <kbd>⌘</kbd>+<kbd>S</kbd> to save the file after it is opened. Further information is available
 [on the issue tracker](https://github.com/eligrey/FileSaver.js/issues/12).
 
-Syntax
-------
+## Syntax
 
-    FileSaver saveAs(in Blob data, in DOMString filename)
+```js
+FileSaver saveAs(in Blob data, in DOMString filename)
+```
 
-Examples
---------
+## Examples
 
 ### Saving text
 
-    var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
-    saveAs(blob, "hello world.txt");
+```js
+var blob = new Blob(["Hello, world!"], {type: "text/plain;charset=utf-8"});
+saveAs(blob, "hello world.txt");
+```
 
 The standard W3C File API [`Blob`][3] interface is not available in all browsers.
 [Blob.js][4] is a cross-browser `Blob` implementation that solves this.
 
 ### Saving a canvas
 
-    var canvas = document.getElementById("my-canvas"), ctx = canvas.getContext("2d");
-	// draw to canvas...
-    canvas.toBlob(function(blob) {
-        saveAs(blob, "pretty image.png");
-    });
+```js
+var canvas = document.getElementById("my-canvas"), ctx = canvas.getContext("2d");
+// draw to canvas...
+canvas.toBlob(function(blob) {
+    saveAs(blob, "pretty image.png");
+});
+```
 
 Note: The standard HTML5 `canvas.toBlob()` method is not available in all browsers.
 [canvas-toBlob.js][5] is a cross-browser `canvas.toBlob()` that polyfills this.