Add an ignore_within option

[DEfusion]

Adds an ignore_within option to provide a selector to ignore elements within. So given the following HTML:

<h1>h1</h1>
<div class="exclude">
  <h2>h2</h2>
  <h3>h3</h3>
</div>
<h4>h4</h4>

With the configuration:

toc:
  ignore_within: .exclude

All headings within the .exclude selector will be ignored.

[toshimaru]

@DEfusion Thanks for sending PR 😍

In the version v0.7.0.alpha1, no_toc feature is released. What about using no_toc class to ignore the toc-headings instead of this ignore_within feature??

[DEfusion]

The no_toc class isn't ideal for my use case where I'm documenting a CSS framework so want to exclude everything within the examples, for instance:

<h2>Titles</h2>
<div class="example">
   <h1 class="title">Title</h1>
   <h2 class="subtitle">Subtitle</h2>
</div>

<h2>Sections</h2>
<div class="example">
   <div class="section">
      <h1 class="title">Title</h1>
      ...
   </div>
</div>

So I'd rather automatically exclude all headings from the toc rather than having to add the no_toc class to each heading within the examples so as to keep the documentation clear regarding the framework HTML & class names.

[toshimaru]

@DEfusion That makes sense, having ignore section would be useful.

Could you rebase the PR to fix conflict?

[toshimaru]

Fixing conflict is needed 💥

[DEfusion]

@toshimaru rebased, no conflicts now.

[toshimaru]

@DEfusion Thanks, let's get this merged.

[toshimaru]

v0.8.0.beta1 released. :)