include defaults for Base.@kwdef structs in FIELDS (or something else)

[tpapp]

In a struct that was defined with Base.@kwdef, is it possible to generate a docstring similar to what FIELDS currently does, but with defaults? MWE:

using DocStringExtensions

"""
$(FIELDS)
"""
Base.@kwdef struct Foo
    a::Int = 1
end

should show something like

• a = 1

I am not even sure if this is conceptually possible though, or if there is a reasonable workaround. Related: #19.