Docs: Added our commit template and instructions

[RobinCsl]

Summary: This commit template is introduced to try and improve our commit message quality; the resulting git history will be more useful and documenting. Instructions on how to set it up were added to the contributing guidelines. (I also think that commit messages should start with a capital letter, so I modified the docs to reflect that.)

[JosefDuda]

universal-components/docs/commit-template.txt

Lines 9 to 15 in 3125713

	# `Fix`: bug fixes, e.g. fix some colors, paddings.
	# `Feat`: new features, e.g. add new component.
	# `Refactor`: code/structure refactor, e.g. new structure folder for components/ extracting component to separate file.
	# `Docs`: changes into documentation,
	# `Test`: adding or updating tests, e.g. unit, snapshot testing.
	# `Chore`: tooling changes, e.g. change circle ci config.
	# `BREAKING`: for changes that break existing usage, e.g. change API of a component.

It will be nice to maintain this block of description only in one place (currently also in CONTRIBUTING.md). But there isn't probably some better way to do it and it won't change much in the future so it's ok for me if we keep it this way.

[RobinCsl]

Yes, ideally it would come from one source of truth.