Import timeknots library

Summary:
Provides a library to draw a minimalist timeline in JS.

Author: Alvaro Graves (alangrafu)
Source: https://github.com/alangrafu/timeknots
License: Apache License 2.0

Fixes T1588.

Test Plan: Test on http://tools51.nasqueron.org/infographics/releases

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1588

Differential Revision: https://devcentral.nasqueron.org/D2197