Add manually annotated publications into LitScan

[carlosribas]

We have several sources of manual paper annotations, GO terms, papers provided by sumbmitters, etc. We should ensure these are included into LitScan and indicated in the facets, possibly as 'manually annotated'.

[carlosribas]

A facet called Manually Annotated has been created, but there are still some articles that were manually annotated that need to be added to LitScan, so I'll keep this issue open