Added graphics for background, ball and paddle
Added ball wall bouncing mechanics
Added paddle movement
Added state reset mechanics
Added ball-paddle interaction
Merge branch 'feature/add_mechanics' into develop
Moved graphics to folder and referenced by constants
Renamed project loader
Rearranged project structure
Code reorganization
Readability enhancement

Targeted to non-rubyist audience.
Added Gemfile for bundler
Added README with installation and launch instructions + Ruby comments
Merge branch 'feature/refactoring' into develop
Minor changes to README
Classes for Background and Ball
Added class for Paddle
Objects list in main class
Moved ball game logic into Ball class
Moved paddle game logic into Paddle class