Added File logger outputter
- Renamed demo images
- Added placeholder file for the demo/public folder
Minor bugfixes
- Fixed YAML parsing error when a file should have a front-matter section
  but it doesnt has it.
- Fixed bug when timestamps where given to the Resource::getDate method
- Renamed items key to count when analizing all the entries
- Minor performance fix to the Indexer class.
- Remove file dates when creating an html link in the Linker class
- Added access to file information on twig variables.
- Added trivial generation test
- Redesigned the test site