Change heading on foreign-travel-advice

[chris-gds]

What

Change to component, alter from h1 to h2 on page: https://www.gov.uk/foreign-travel-advice/afghanistan

Why

The problem is that in part-separated content we have two h1 headings, one for the guide name, then one for the part name, and then the content is displayed with h2 headings. Make the guide heading a h2 even though it comes before the part heading. This is not ideal as it's a slightly confusing structure but does not violate any standards and it leaves the h1 as the most relevant title on the page.

Visual changes

None

Anything else

Ideally the Content under the h2 should now be updated to h3 however this lives within govspeak controlled by Content teams. Been made aware there are 226 different guides to update.
https://www.gov.uk/foreign-travel-advice/afghanistan