V0.1.1 patch notes: easier practice mode

RogueBlock (working title) V0.1.1 update

I've gotten feedback that, even in practice mode, the game is very difficult.
In this patch, I've tweaked the attack patterns of all enemies when in practice mode.

This differs per enemy, but generally, in when practice mode you will see:

    - Longer intervals between attacks

    - Fewer bullets on screen at the same time

    - Certain attacks are slightly slower

Additional Changes:

    - Hermit crab 'cone' attack now covers a wider area of the screen.

Bug Fixes:

    - Fixed issue where 'Silver Bullet' ability would not actually double the damage of your charged bullets in certain causes

    - Fixed issue where a chest could spawn on a tile that would prevent you from moving to the next location