Document dependency on autoprefixer or warn about its usage

This is about the Docs.

Is it a bug/feature/question or do you need help?
It's a bug.

If it's a bug, is it a browser bug?
Not a browser bug, but relates to browser support.

Overview of the problem

This is about the Bulma Docs.

I'm using Bulma version [0.9.3], master branch.

I am sure this issue is not a duplicate?
Searched the issues for autoprefixer, haven't found anything.

Description

The documentation page on Customization with node-sass, in its section 2-Install the dev dependencies says "you only need 2 packages to customize Bulma: node-sass and bulma itself". The described workflow doesn't include running autoprefixer, and the resulting generated bulma.css is different from the official one (I count 11 different properties, mainly related to animation).

The docs should either make it clear that autoprefixer is also a dependency, or at least warn that css files produced without it might be different from the official one.

Steps to Reproduce

Follow the steps on this page, up to "To test it out, go in your terminal and run the following command: npm run css-build".
Compare the generated css file with bulma.css

Expected behavior

With no customization, users expect the files to be the same.

Actual behavior

Files differ on the following browser-prefixed properties:

-webkit-animation: spinAround 500ms infinite linear;
-webkit-text-size-adjust: 100%;
-moz-text-size-adjust: 100%;
@-webkit-keyframes spinAround {...}
-webkit-animation-duration: 1.5s;
-webkit-animation-iteration-count: infinite;
-webkit-animation-name: moveIndeterminate;
-webkit-animation-timing-function: linear;
@-webkit-keyframes moveIndeterminate {...}
min-height: -webkit-min-content;
min-height: -moz-min-content;

jgthms / bulma