Indexible content snippet for people pages, manual description for departments.

Deep links for organisations and person roles
rich results/metadata for document series, minister, people, world location and worldwide organisation

- minor style fix for .sections list items
- 'document series' displays indexable content
- 'organisation' displays indexable content
- 'minister' displays indexable content and anchors to responsibilities
and current role holder
- 'person' displays indexable content and anchors to biography and roles
- 'world location' displays indexable content and anchors to priorities
and organisations
- 'worldwide organisations' displays indexable content and anchors to
services and contact details
make mainstream result description visible if crumbtrail available

- by moving the result description out of the crumbtrail 'if statement'
- move whitespace from crumbtrail/metadata to h3, so that the spacing
is correct when crumbtrail not present
Clean up displaying summary content

Moved the calculation of truncating the indexable content out of the template and into the presenter.
Remove display of deep links for No10 and DPMO

These organisations do not have available content for the relevant deep links, hence removing them.
Merge pull request #350 from alphagov/organisation-metadata

Indexible content snippet for people pages, manual description for depar...