added bower to common pages

pages/common/bower.md

@@ -0,0 +1,32 @@
+# bower
+
+> A package manager optimized for front-end web development.
+> A package can be a GitHub user/repo shorthand, a Git endpoint, a URL or a registered package.
+
+- Install a project's dependencies, listed in its bower.json:
+
+`bower install`
+
+- Install one or more packages to the bower_components directory:
+
+`bower install {{package}} {{package}}`
+
+- Uninstall packages locally from the bower_components directory:
+
+`bower uninstall {{package}} {{package}}`
+
+- List local packages and possible updates:
+
+`bower list`
+
+- Display help information about a bower command:
+
+`bower help {{command}}`
+
+- Create a bower.json file for your package:
+
+`bower init`
+
+- Install a specific dependency version, and add it to bower.json:
+
+`bower install {{local_name}}={{package}}#{{version}} --save`