Version 0.20.1: Catchable errors for zero-sided dice

[Samasaur1]

Here's what's new:

• Documentation deployment is fixed
• Complies with SwiftLint (not naming an untyped error, which is redundant)
• Errors thrown by the Die(sides:) initializer correctly propagate through the Dice(_: String) initializer. Specifically, this throws (instead of crashing on) an error for trying to create dice with zero sides.

Here's what has to happen:

• [x] Write tests for this feature
• [x] Ensure the changelog has everything new that is being added

[Samasaur1]

Additionally, it correctly implements the description for Error

[Samasaur1]

	Warnings
:warning:	Test files were changed, but LinuxMain wasn't! This could be okay, if you just changed tests, but if you added any, run `swift test --generate-linuxmain` to update LinuxMain
:warning:	Sources/DiceKit/Enums.swift was changed, but there is no file at path Tests/DiceKitTests/EnumsTests.swift. Maybe it's under a different path, or maybe there are no tests

	Messages
:book:	Sources/DiceKit/Dice.swift has had corresponding changes in its test file
:book:	Sources/DiceKit/Chance.swift has had corresponding changes in its test file
:book:	The latest date in the CHANGELOG is today, 2020-06-30
:book:	The new version is v0.20.1

Generated by :no_entry_sign: Danger Swift against 4df5784cf65a47cf4df2c9aa808afb9d81a4cd58