Fixed documentation in relation with new permalink specification

For more information about the new permalink strategy

 * https://github.com/farazdagi/phrozn/pull/73

In practice the new permalink structure needs the result file extension
in order to create a correct file.
Moved resources to support Composer autoloader
Merge pull request #8 from wdalmut/hotfix/parametrized-extensions

Use permalink if exists instead append .html