Hide heading attributes in sidebar navigation

Some Markdown dialects (I'm using Pandoc) allow headings to be tagged various ways, often adding an ID tag, sometimes a class, and in my case even some other meta data (timestamps corresponding to the location in a video file).

This information clutters up the sidebar header navigation considerably. Anything in {} braces after headers should probably be filtered out of that view.

For example the following Markdown:

# Heading {#top}

Content

...should not show the ID attribute markup ({#top}) in the sidebar. Here's an example of what it starts looking like:

Start by tracing the sidebar header navigation and how Markdown headings are parsed or rendered there; the issue provides the {#top} example as the expected input. Done means attributes in braces after headings no longer appear in the sidebar while the heading text remains visible.