Formatting regression in code blocks

[kristianfreeman]

Since be06f10, there appears to be a regression in how code blocks are formatted in our docs. This change causes extraneous whitespace on properly-spaced code (example image below).

The offending code seems to be this new <br /> tag here:

cloudflare-docs-engine/src/components/mdx/code-block.js

Lines 129 to 131 in be06f10

	<span className="CodeBlock--token-plain">
	<br />
	</span>

Here's an example in a new tutorial we launched for Workers: