Remove content that can be now be found on bower.io

+ bower.json
+ custom install directory
+ bower search
+ using bower cache
+ .bowerrc
+ continuous integration server
+ interactive configuration
+ Defining a package
+ maintaining deps
+ consuming a package
+ programmatic api
+ assistance & contribution list

Ref #1371
Merge pull request #1415 from bower/simple-readme

Remove content that can be now be found on bower.io