add build custom doc

Author: yiminghe

README.md

@@ -20,6 +20,10 @@ bower install
 npm run build
 ```
 
+## Build your own modules
+
+https://github.com/kissyteam/kissy/blob/master/build-your-own-modules.md
+
 ## Modules
 
 [http://kissyteam.github.io/badgeboard/](http://kissyteam.github.io/badgeboard/)

build-your-own-modules.md

@@ -0,0 +1,52 @@
+# build your own modules
+
+KISSY 5 is a collection of independent modulex modules now, if you do not like all of its modules in KISSY 5,
+you can build your own modules, as a bonus, you can control each module's version.
+
+
+## create bower.json
+
+Create bower.json and fill its ``dependencies`` field with the specified versioned modules you what.
+
+For example: I only want to use loader and anim module
+
+```javascript
+{
+  "name":"my-kissy",
+  "dependencies": {
+    "modulex":"1.6.2",
+    "modulex-anim":"1.0.2"
+  }
+}
+```
+
+## create package.json
+
+Require ``aggregate-bower`` modules
+
+For example:
+
+```javascript
+{
+  "name":"my-kissy",
+  "dependencies": {
+    "aggregate-bower": "^1.0.9"
+  }
+}
+```
+
+## create build.js
+
+Copy https://github.com/kissyteam/kissy/blob/master/build.js to your folder
+
+## build
+
+Run the following command:
+
+```
+npm install
+bower install
+node build
+```
+
+The files in ``build/`` folder is what you want, you can load ``build/seed.js`` and use your own custom kissy version.

build.js

@@ -5,7 +5,7 @@ var buildDir = path.resolve(process.cwd(), 'build');
 var aggregateBower = require('aggregate-bower');
 var inferBaseCode = 'modulex.init({name:"seed"});';
 var kgConfigContent = 'modulex.config({ packages : { kg : { base : "//g.alicdn.com/kg/" }}});';
-var extraContent = ['',inferBaseCode,kgConfigContent].join('\n');
+var extraContent = ['', inferBaseCode, kgConfigContent].join('\n');
 
 function generateSeedJs() {
     var seedDebugJsContent = '',
@@ -14,10 +14,11 @@ function generateSeedJs() {
     for (var i = 0; i < filesList.length; i++) {
         var debugFilePath = path.join(buildDir, filesList[i] + '-debug.js'),
             miniFilePath = path.join(buildDir, filesList[i] + '.js');
-        seedDebugJsContent += fs.readFileSync(debugFilePath).toString();
-        seedJsContent += fs.readFileSync(miniFilePath).toString();
+        if (fs.existsSync(debugFilePath)) {
+            seedDebugJsContent += fs.readFileSync(debugFilePath).toString();
+            seedJsContent += fs.readFileSync(miniFilePath).toString();
+        }
     }
-
     fs.writeFileSync(path.join(buildDir, 'seed-debug.js'), seedDebugJsContent + extraContent);
     fs.writeFileSync(path.join(buildDir, 'seed.js'), seedJsContent + extraContent);
 }