0.0.3 - QoL #2 & more

First let's get the QoL out of the way:

• Added in faded blocks showing clearly the goal of each level. This adds in the minor extra restriction of having to make the shape in the location specified not anywhere you want but makes the goal much easier to see (and the coding much easier on my end).
• You can now press the number keys (1, 2, 3, 0) to select items from your inventory. I'm pretty sure it works splendidly...

What's the '& more' about?

• So I added in the most rudimentary and non-functional level select screen. We'll get art for it and more levels ASAP.