README: improve markdown formatting
README: improve markdown formatting

* Use syntax highlighting for puppet example
* Use literal tags for inline samples
* Add links to chocolatey and puppet web sites

ferventcoder/puppet-chocolatey,korytkoBT/puppet-chocolatey,idoru78/puppet-chocolatey,maxgaulhofer/puppet-chocolatey,9bryan/puppet-chocolatey,rismoney/puppet-chocolatey,chocolatey/puppet-chocolatey,ferventcoder/puppet-chocolatey,krutisfood/puppet-chocolatey,korytkoBT/puppet-chocolatey,idoru78/puppet-chocolatey,maxgaulhofer/puppet-chocolatey,cregev/puppet-chocolatey,cregev/puppet-chocolatey,chocolatey/puppet-chocolatey,rismoney/puppet-chocolatey,9bryan/puppet-chocolatey,ThoughtCrhyme/puppetlabs-chocolatey,ThoughtCrhyme/puppetlabs-chocolatey