Code formatting (and linting) in precommit hook

[mspae]

Short description of changes:

• This PR contains no functional change to the library itself.
• Adds prettier for consistent formatting
• Eslint config was adjusted to check for correct formatting
• Added Precommit hook to autoformat (and lint) code before it enters the repo (as detailed here)

Breaking in the external API:

/

Breaking changes in the internal API:

/

Todos/Notes:

No further configuration is needed to get the hook working. Simply check out this code and npm install – All future code will be formatted and linted before it is commited. (It will also fail to commit if there are linting issues)