Release v4.3.0 (#28228)

* Prep for v4.3.0

* More updates for v4.3.0.

* rerun to build docs source map

site/docs/4.3/content/code.md

@@ -0,0 +1,55 @@
+---
+layout: docs
+title: Code
+description: Documentation and examples for displaying inline and multiline blocks of code with Bootstrap.
+group: content
+toc: true
+---
+
+## Inline code
+
+Wrap inline snippets of code with `<code>`. Be sure to escape HTML angle brackets.
+
+{% capture example %}
+For example, <code>&lt;section&gt;</code> should be wrapped as inline.
+{% endcapture %}
+{% include example.html content=example %}
+
+## Code blocks
+
+Use `<pre>`s for multiple lines of code. Once again, be sure to escape any angle brackets in the code for proper rendering. You may optionally add the `.pre-scrollable` class, which will set a max-height of 340px and provide a y-axis scrollbar.
+
+{% capture example %}
+<pre><code>&lt;p&gt;Sample text here...&lt;/p&gt;
+&lt;p&gt;And another line of sample text here...&lt;/p&gt;
+</code></pre>
+{% endcapture %}
+{% include example.html content=example %}
+
+## Variables
+
+For indicating variables use the `<var>` tag.
+
+{% capture example %}
+<var>y</var> = <var>m</var><var>x</var> + <var>b</var>
+{% endcapture %}
+{% include example.html content=example %}
+
+## User input
+
+Use the `<kbd>` to indicate input that is typically entered via keyboard.
+
+{% capture example %}
+To switch directories, type <kbd>cd</kbd> followed by the name of the directory.<br>
+To edit settings, press <kbd><kbd>ctrl</kbd> + <kbd>,</kbd></kbd>
+{% endcapture %}
+{% include example.html content=example %}
+
+## Sample output
+
+For indicating sample output from a program use the `<samp>` tag.
+
+{% capture example %}
+<samp>This text is meant to be treated as sample output from a computer program.</samp>
+{% endcapture %}
+{% include example.html content=example %}