Prep for v4.2.0 release

- Move 4.1 docs to 4.2
- Update versions everywhere to 4.1.3 with release script
- Manually bump the shorthand version in package.json
- Add 4.2 to the versions docs page
- Update some redirects
- Fix tests asset URLs
- Bump Nuget and more

site/docs/4.2/utilities/image-replacement.md

@@ -0,0 +1,37 @@
+---
+layout: docs
+title: Image replacement
+description: Swap text for background images with the image replacement class.
+group: utilities
+toc: true
+---
+
+{% capture callout %}
+##### Warning
+
+The `text-hide()` class and mixin has been deprecated as of v4.1. It will be removed entirely in v5.
+{% endcapture %}
+{% include callout.html content=callout type="warning" %}
+
+Utilize the `.text-hide` class or mixin to help replace an element's text content with a background image.
+
+{% highlight html %}
+<h1 class="text-hide">Custom heading</h1>
+{% endhighlight %}
+
+{% highlight scss %}
+// Usage as a mixin
+.heading {
+  @include text-hide;
+}
+{% endhighlight %}
+
+Use the `.text-hide` class to maintain the accessibility and SEO benefits of heading tags, but want to utilize a `background-image` instead of text.
+
+<div class="bd-example">
+  <h1 class="text-hide" style="background-image: url('{{ site.baseurl }}/docs/{{ site.docs_version }}/assets/brand/bootstrap-solid.svg'); width: 50px; height: 50px;">Bootstrap</h1>
+</div>
+
+{% highlight html %}
+<h1 class="text-hide" style="background-image: url('..');">Bootstrap</h1>
+{% endhighlight %}