Add support for a footer which makes VB use the body of the commit in changelog

[nazrhom]

It would be nice to have a special footer which tells versionist to create a changelog entry that uses the body of the commit rather than the subject. It could still show the subject expandable to the whole body

[nazrhom]

This is a bit awkward to implement as it would have to build into the template with conditionals (can't even switch templates based on the presence of the flag as this is a commit-specific setting)

[pdcastro]

to create a changelog entry that uses the body of the commit rather than the subject

Maybe it is what was meant anyway, but I imagine that the subject line would always be included, whether or not it "expands" to the body of the commit.

[pdcastro]

Maybe not for versionist, perhaps resinci-deploy: the product call also decided that it would be nice to have the extended descriptions (commit body paragraphs) added to release descriptions in the GitHub releases page.

[lurch]

it would have to build into the template with conditionals

Does https://github.com/helpers/handlebars-helpers#comparison allow you to do that?