Typos found in the public docs.

[e-dwar]

The comments says xs, ys and zs while variables are called source, fork1 and fork2:

highland/dist/highland.js

Line 1718 in 2eb6437

  * // No values will be pulled from xs until zs also starts consuming. 

Found here: https://highlandjs.org/#fork

[Victor Vu]

Fixed. Thanks for reporting!