Labels to links

[klauspaiva]

Checklist

• ✅ The code has been run through pretty yarn run pretty
• ✅ The tests pass on CircleCI
• ✅ You have referenced the issue(s) or other PR(s) this fixes/relates-to
• ✅ The PR Template has been filled out (see below)
• ✅ Had a beer because you are awesome

What?

Introduces the functionality to add a plain text label to links.
Following the discussion from: #140

Why?

Especially useful when you're implementing something like a state machine.

How?

The initial plan was to use SVG's textPath, but it then follows the orientation of the referenced path, which makes text incredibly hard to read.

Achieved the desired result by using a combination of getPointAtLength and getTotalLength.
Implementation had to account for multiple segments (paths), which made the algorithm slightly more complex to follow, but still simple enough.

Feel-Good "programming lol" image:

Source: http://codingatschool.weebly.com/programming-project.html

[emero]

@dylanvorster would it be possible to release a version that has these commits? 🙇