This is a bit of an edge case, but it would be great to be able to have uncss ignore sections/elements within the html. My thought is that it'd be nice to add a class (eg. ".uncss-ignore") to an element and have uncss not include it in its processing.

Our use case is that we're using the html our pattern library exports for uncss' reference. The html includes a lot of examples and reference components that may or may not end up being used in an actual pattern.

Example use:

<!-- .c-component rule would be removed, because uncss ignored the section -->
<div class="uncss-ignore c-component"></div>

<!-- .c-component rule would NOT be removed -->
<div class="c-component"></div>

I have a POC working. It works by removing elements with the 'uncss-ignore' class from the DOM before the call to findAll in getUsedSelectors. I'll submit a PR soon for you to take a look at.