Changes:
- content files moved to .phtml extension
- PHP functions and config file moved to includes folder
- site_url introduced to solve the URL issues
- content files are not loaded through "file_get_contents" instead of "include"
- styles moved to separate stylesheet file
- PHP introductory course linked in readme
- renamed main run() file to init()
- rewrote camelCase() functions to snake_case()
- introduced error reporting

Signed-off-by: Baki Goxhaj <[email protected]>