Bugfix, added `format`function, changed `sum` to `add`

- Fixed a bug where throwing an error would throw an error (wat?)
- Added function `format`; a slimmed down version of `sprintf`.
- Renamed `sum` to `add`, to better suit its functionality.
Bugfixes with object creation and piping

- Fixed a bug where defining an object key with a variable value would throw.
- Fixed incorrect behavior when piping multiple results.
- Added tests to prove fixes.
Documentation

- Spiced up the page layout a bit.
- Started working on manual text.