add more instructions in installation

README.md

@@ -1,11 +1,9 @@
-Asciidoc-deck.js
-================
+# Asciidoc-deck.js
 
 A Deck.js backend for asciidoc. 
 
 
-Dependencies
-------------
+## Dependencies
 
 * AsciiDoc
 * Deck.js
@@ -15,18 +13,16 @@ Optional:
 * If you want to highlight source code, please install Pygments or source-highlight.
 
 
-Installation
-------------
+## Installation
 
-If you don't have deck.js you can download it automatically with `make install`. Or you can get it manually from its official [link](https://github.com/imakewebthings/deck.js/zipball/stable), and rename the unzipped directory to `deck.js`.
+If you don't have deck.js you can download it automatically with `make install`. Or you can get it manually from its official [link][deckjs], and rename the unzipped directory to `deck.js`. (when installing with make, you also get some other deck.js extensions.)
 
-The second thing you need to do is to make sure your asciidoc can properly find `deckjs.conf`. For asciidoc's configuration file loading strategy, please refer to [this guide](http://www.methods.co.nz/asciidoc/userguide.html#X7).
+The second thing you need to do is to make sure your asciidoc can properly find `deckjs.conf`. For asciidoc's configuration file loading strategy, please refer to [this guide][asc-conf-guide].
 
 The easiest way is to put `deckjs.conf` and the asciidoc file you wrote in the same directory.
 
 
-Usage
------
+## Usage
 
 ```bash
 asciidoc -f deck.js.conf file.asciidoc
@@ -37,3 +33,5 @@ file.asciidoc is the asciidoc file you wrote.
 Remember to put `deck.js`, `ad-stylesheet` and generated slide into the same directory.
 
 
+[deckjs]:https://github.com/imakewebthings/deck.js/zipball/stable
+[asc-conf-guide]:http://www.methods.co.nz/asciidoc/userguide.html#X7