Switch to Hugo

This commit includes all the needed workarounds and most changes from the main branch for everything to work, like:

* removing empty lines in raw HTML that break output
* read .browserslistrc, CSS variables from disk instead of duplicating it
* using Hugo mounts
* using Hugo for the docs CSS/JS
* move ToC Sass code to a separate file while adapting it for Hugo

Thus, this patch makes our npm scripts faster since lint runs on one step and there's no separate docs assets processing.

site/content/docs/4.5/utilities/float.md

@@ -0,0 +1,60 @@
+---
+layout: docs
+title: Float
+description: Toggle floats on any element, across any breakpoint, using our responsive float utilities.
+group: utilities
+toc: true
+---
+
+## Overview
+
+These utility classes float an element to the left or right, or disable floating, based on the current viewport size using the [CSS `float` property](https://developer.mozilla.org/en-US/docs/Web/CSS/float). `!important` is included to avoid specificity issues. These use the same viewport breakpoints as our grid system. Please be aware float utilities have no effect on flex items.
+
+## Classes
+
+Toggle a float with a class:
+
+{{< example >}}
+<div class="float-left">Float left on all viewport sizes</div><br>
+<div class="float-right">Float right on all viewport sizes</div><br>
+<div class="float-none">Don't float on all viewport sizes</div>
+{{< /example >}}
+
+## Mixins
+
+Or by Sass mixin:
+
+```scss
+.element {
+  @include float-left;
+}
+.another-element {
+  @include float-right;
+}
+.one-more {
+  @include float-none;
+}
+```
+
+## Responsive
+
+Responsive variations also exist for each `float` value.
+
+{{< example >}}
+<div class="float-sm-left">Float left on viewports sized SM (small) or wider</div><br>
+<div class="float-md-left">Float left on viewports sized MD (medium) or wider</div><br>
+<div class="float-lg-left">Float left on viewports sized LG (large) or wider</div><br>
+<div class="float-xl-left">Float left on viewports sized XL (extra-large) or wider</div><br>
+{{< /example >}}
+
+Here are all the support classes;
+
+{{< markdown >}}
+{{< float.inline >}}
+{{- range $.Site.Data.breakpoints }}
+- `.float{{ .abbr }}-left`
+- `.float{{ .abbr }}-right`
+- `.float{{ .abbr }}-none`
+{{- end -}}
+{{< /float.inline >}}
+{{< /markdown >}}