Fix some unintentional anchor links

These links worked in the manuals-frontend alpha which showed all subsections
on the page of their parent section. These examples were copied from the data
that was put together to power the alpha, but these links should have been
changed.
Better section titles in search results

At the moment, sections appearing in search results don't identify themselves
very well because they are just the section title itself, which, based on the
existing HMRC manuals on www.hmrc.gov.uk, would be things like "Definition of a
Chapter 2 lease". With this change, you can see that it is an HMRC Manual, and
if you searched by section ID, you see that in the search result to help you
identify it.
Merge pull request #73 from alphagov/better_section_titles_in_search_results

Better section titles in search results
Merge pull request #71 from alphagov/fix_unintended_anchor_links

Fix some unintentional anchor links in examples
HMRC Manuals have a custom prefix on GOV.UK

As the HMRC manuals are not general government guidance on tax and benefits,
the agreement is that they should be treated as a special case.