Add missing get/set types, improve documentation

[rijkvanzanten]

Fixes #109

Also added some inline documentation, in order to have supported editors render useful information inline where the methods are used:

I ran prettier for formatting consistencies sake. There doesn't seem to be an editorconfig or linting setup, so my setup defaulted to tabs w/ 80-column width. Lemme know if you prefer that otherwise.

[coveralls]

Pull Request Test Coverage Report for Build 316

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 84.853%

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Totals
Change from base Build 314:	0.1%
Covered Lines:	1047
Relevant Lines:	1209

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💛 - Coveralls

[animir]

@rijkvanzanten Wow, that's great 😍 Thank you!

Could you replace all tabs to 4 spaces? Btw, I created an issue for editorconfig #111

[rijkvanzanten]

All set!

[animir]

@rijkvanzanten 👍