Embedded Unsplash images are broken

[theodorejb]

This is a bug in the Bulma Docs, and I'm sure this issue is not a duplicate.

Description

While reading https://bulma.io/documentation/sass/mixins/#center, I noticed that the center() mixin example has a broken image:

The image src is https://source.unsplash.com/mEZ3PoFGs_k/192x192, which is a broken link.

I checked for other usages of source.unsplash.com, and found there are 8 total references in the code, all of which are broken.

• The overlay() mixin example has a broken background-image: url(https://source.unsplash.com/La2kOu2dmH4/640x320);).
• The center() mixin example also has a broken background-image: url(https://source.unsplash.com/xo3Bd2tYeqg/640x320); (separate from the broken <img> I noticed first).
• The clearfix() mixin example has a broken image (src="https://source.unsplash.com/La2kOu2dmH4/160x160")
• The https://bulma.io/brand/ page has a bunch of broken background images on various .bd-logos-item divs (view page source and search for source.unsplash.com).
• Blog posts with a post.image defined display a broken image (e.g. https://versions.bulma.io/0.9.4/2018/04/13/website-redesign/)

Steps to Reproduce

Open https://bulma.io/documentation/sass/mixins/#center, https://bulma.io/brand/, or https://versions.bulma.io/0.9.4/2018/04/13/website-redesign/ and notice the broken/missing images.

(Side note: blog posts don't seem to load at all on the latest version of the site. E.g. https://bulma.io/2018/04/13/website-redesign/ only displays "How to support Bulma". But this is a separate bug.)

Expected behavior

Needed images should probably be hosted together with the docs rather than relying on a third-party site which can break at any time.

Actual behavior

Images fail to load.