Highlighting and Auto-Focus in Code and Crumbs section of sidebar

[magic-m-johnson]

Having multiple crumbs in one large file without it jumping to the respective comment in the code or crumb in the sidebar can result in a little tedious manual searching.

Also, highlighting in Code preview would also be sweet, as well as the option to close/open all crumbs (or just having the active one open [e.g. close current -> open next]).

Basically, some auto-focus features for the sidebar panels.