Update documentation so that help files can be found

[nehill197]

When looking up the help file for analyse, all that comes up is the generic.
It would be ideal to have the class definitions appear as you type "?analyse".
e.g. would like ?analyse.mb_model to appear.

[sebdalgarno]

bumping this - agree it is not straightforward to find documentation for embr functions
I think part of the issue is that the generics are internal functions - so have to do
?embr:::analyse.mb_model instead of ?embr::analyse.mb_model

I think the best solution would be to do ?embr::analyse and display links to documentation for each S3 method