132 docstrings not included in the manual

When building the manual one gets the message "132 docstrings not included in the manual".

In fact with Documenter 1.x this is an error by default, so I had to set warnonly = true in docs/make.jl for now.

One can pass checkdocs = : exports to makedocs(), then the number of warnings goes down to 70+ but that's still quite a bit.

    DataStructures.counter :: Tuple{Any}
    DataStructures.prefixsum :: Union{Tuple{T}, Tuple{FenwickTree{T}, Integer}} where T
    DataStructures.incdec! :: Union{Tuple{T}, Tuple{FenwickTree{T}, Integer, Integer}, Tuple{FenwickTree{T}, Integer, Integer, Any}} where T
    DataStructures.find_prefixes :: Union{Tuple{T}, Tuple{Trie, T}} where T
    Base.length :: Tuple{BinaryHeap}
    Base.length :: Tuple{CircularBuffer}
    DataStructures.heappop! :: Union{Tuple{AbstractArray}, Tuple{AbstractArray, Base.Order.Ordering}}
    DataStructures.CircularBuffer
    DataStructures.find_root! :: Union{Tuple{T}, Tuple{IntDisjointSet{T}, T}} where T<:Integer
    DataStructures.find_root! :: Union{Tuple{T}, Tuple{DisjointSet{T}, T}} where T
    DataStructures.DefaultDict
    DataStructures.capacity :: Tuple{CircularBuffer}
    DataStructures.capacity :: Tuple{CircularDeque}
    DataStructures.nextreme :: Union{Tuple{T}, Tuple{Base.Order.Ordering, Int64, AbstractVector{T}}} where T
    DataStructures.rb_transplant :: Tuple{RBTree, Union{Nothing, DataStructures.RBTreeNode}, Union{Nothing, DataStructures.RBTreeNode}}
    DataStructures.FasterReverse
    DataStructures.Accumulator
    DataStructures.extract_all_rev! :: Union{Tuple{AbstractHeap{VT}}, Tuple{VT}} where VT
    Base.empty! :: Tuple{CircularBuffer}
    Base.last :: Tuple{CircularBuffer}
    Base.last :: Tuple{CircularDeque}
    Base.getkey :: Union{Tuple{Ord}, Tuple{D}, Tuple{K}, Tuple{SortedDict{K, D, Ord}, Any, Any}} where {K, D, Ord<:Base.Order.Ordering}
    Base.getkey :: Union{Tuple{V}, Tuple{K}, Tuple{RobinDict{K, V}, Any, Any}} where {K, V}
    Base.getkey :: Union{Tuple{V}, Tuple{K}, Tuple{OrderedRobinDict{K, V}, Any, Any}} where {K, V}
    Base.getkey :: Union{Tuple{V}, Tuple{K}, Tuple{SwissDict{K, V}, Any, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{RobinDict{K, V}, Any, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{Union{Function, Type}, RobinDict{K, V}, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{OrderedRobinDict{K, V}, Any, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{Union{Function, Type}, OrderedRobinDict{K, V}, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{SwissDict{K, V}, Any, Any}} where {K, V}
    Base.get :: Union{Tuple{V}, Tuple{K}, Tuple{Union{Function, Type}, SwissDict{K, V}, Any}} where {K, V}
    Base.popfirst! :: Tuple{CircularBuffer}
    Base.popfirst! :: Tuple{CircularDeque}
    Base.merge! :: Union{Tuple{Ord}, Tuple{D}, Tuple{K}, Tuple{SortedMultiDict{K, D, Ord}, Vararg{Any}}} where {K, D, Ord<:Base.Order.Ordering}
    Base.merge! :: Tuple{Accumulator, Accumulator}
    DataStructures.isheap :: Union{Tuple{AbstractArray}, Tuple{AbstractArray, Base.Order.Ordering}}
    DataStructures.is_minmax_heap :: Tuple{AbstractVector}
    DataStructures.OrderedRobinDict
    Base.haskey :: Tuple{SwissDict, Any}
    Base.haskey :: Union{Tuple{K}, Tuple{RBTree{K}, K}} where K
    Base.haskey :: Tuple{RobinDict, Any}
    Base.haskey :: Tuple{OrderedRobinDict, Any}
    Base.isempty :: Tuple{BinaryHeap}
    Base.isempty :: Tuple{CircularBuffer}
    Base.first :: Tuple{BinaryHeap}
    Base.first :: Tuple{CircularBuffer}
    Base.first :: Tuple{BinaryMinMaxHeap}
    Base.first :: Tuple{CircularDeque}
    Base.setindex! :: Tuple{CircularBuffer, Any, Int64}
    DataStructures.heapify! :: Union{Tuple{AbstractArray}, Tuple{AbstractArray, Base.Order.Ordering}}
    DataStructures.insert_node! :: Tuple{RBTree, DataStructures.RBTreeNode}
    DataStructures.left_rotate! :: Tuple{RBTree, DataStructures.RBTreeNode}
    Base.pop! :: Union{Tuple{V}, Tuple{K}, Tuple{RobinDict{K, V}, Any, Any}} where {K, V}
    Base.pop! :: Tuple{BinaryHeap}
    Base.pop! :: Tuple{OrderedRobinDict, Any, Any}
    Base.pop! :: Tuple{SwissDict, Any}
    Base.pop! :: Tuple{BinaryMinMaxHeap}
    Base.pop! :: Tuple{CircularBuffer}
    DataStructures.top_with_handle :: Tuple{MutableBinaryHeap}
    DataStructures.minimum_node :: Tuple{RBTree, DataStructures.

Start with docs/make.jl and run the manual build using Documenter, reviewing the listed missing docstrings and the effect of checkdocs = :exports. Trace each warning to the corresponding documented API, then verify the build no longer requires warnonly = true and the missing-docstring warnings are resolved.