Fix section links on right navigation bar, which don't work when punctuated

[zakpatterson]

Ids are rendered differently when parsed from markdown and rendered, from when they are inserted into the vector that populates the right navigation bar. As a result, links on the right navigation bar do not work if they contain punctuation, or any characters besides [0-9a-zA-Z\-].

For example. on the page https://dioxuslabs.com/learn/0.6/, clicking the link Who's funding dioxus? appends #who's-funding-dioxus? to the url, but that anchor is rendered with the id="whos-funding-dioxus".

So I just took the code that renders id for the section based on the title, and replicated it for the code that inserts the sections into the vector that populates the menu. Unfortunately these two Section structs are different, and the one that is used in rendering the page is private.

[zakpatterson]

There is a separate issue when there are ! and () inside an article title markdown, as in this page, and the "Stabilizing Manganis" title. The whole title text is not parsed and available in the text variable at this point.