1 essential tip: How to use table of content feature how about super long title that goes like this

First article heading H2

Only H2 headings appear in the table of contents. What happens for any other ones? Let's try this:

This is a heading 3

And it's invisible in the table of contents! Because h3 and all the lower ones are subsections of the H2s.

Here goes the heading 4

Invisible again in the table of contents.

Heading 5 looks like this

You guessed it. Invisible in the table of contents.

Second article heading H2

Here we can see only h2s appear.

Yet another heading 2 for a good measure.