Version 0.3.0: Multiplication

[Samasaur1]

Both Die and Dice can now be multiplied with Int. Examples:

let d6 = Die.d6
let threeD6 = d6 * 3
threeD6.debugDescription // 3d6

let dFourPlusFour = Die.d4 + 4
let threeTimesIt = dFourPlusFour * 3
threeTimesIt.debugDescription // 3d4 + 12

Version 0.2.0 additions also now have documentation (d70a925). These additions don't because they aren't documented at all.

Closes #10 and closes #11

[Samasaur1]

Updating version...

[Samasaur1]

Next steps:

1. Wait for CI
2. Merge
3. git tag -s v0.3.0 -m "Version 0.3.0: The Multiplication Update"
4. git push --tags
5. git checkout development and git rebase master
6. git push

[Samasaur1]

Because I did a squash merge instead of a merge commit, I deleted and recreated the development branch and then did a hard reset to it from my local repo to avoid a merge commit.

[Samasaur1]

I also forgot to say that I needed to close the Multiplication milestone, which I'm doing now