Dev Docs (Formatting Only): Convert Fake Subheadings To Real Subheadings

Converts fake subheadings created using **bold** to real HTML
subheadings without adding them to the table of contents.

Also fixes a link broken by commit 4e067ac89e74b and adds a Makefile
test to catch future similar breakage.
Ignore .no_toc titles when selecting active toc entry
Allow links in anchor affordance titles
Merge remote-tracking branches 'saivann/notoc' and 'saivann/notocanchor' into notoc
Dev Docs: Revise Makefile Test To Check For Auto Links In Subheadings
Merge branch 'notoc' (Pull #661: Convert Fake Subheadings To Real Subheadings)