Add index.html
Add block.ts, shape.ts and main.ts files
Remove reference tags from ts files
Ignore compiled tetris.js file and add reference to index.html
Define Block class
Add settings.ts and shape_defs.ts files
Add some settings
Add definition for line and square shapes
Add move method to Block
Define shape class
Adjust Block's coordinates to always be in pixels rather than tiles
Fix condition in Shape's draw method
Fix order in which blocks are drawn
Add a test shape
Add npm package and build system
Add remaining shape definitions and description
Add init, update and draw functions to main.ts