This plugin uses OCamlbuild to generate a build system. It is the default value
for `BuildType`.


It is also possible to use this plugin for `Document.Type` which is the
default. In this case, OCamlbuild will also be involved in the generation of a
particular document.

Package fields:

$ListOCamlbuildBuildPackageFields

Document fields:

$ListOCamlbuildDocDocumentFields
