Build 22: powerups!

I’ve worked a bit on the game today on stream.

What’s new:

• Basic powerup system: some blocks will have a white or black particle effect; those are powerups that activate when removed as a part of a combo.
• Black powerup: diagonal selection allowed for 60 seconds - thanks to @flaviuskid for the suggestion!
• White powerup: chain selection (selection can continue if the current and previous block has the same symbol or colour) allowed for 60 seconds - thanks to @mmyse for the suggestion!
• Haptic feedback when selecting blocks & making combos (might not work on all browsers, eg. Firefox on Android) - thanks to @iheartfunnyboys for the suggestion
• Text UI which shows how many points you get for a combo (and multicolour bonus if applicable)
• Smooth health bar animation