Packages that provide most of their functionality in association with a new type should have pluralized names.
DataFrames provides the DataFrame type.
BloomFilters provides the BloomFilter type.
In contrast, JuliaParser provides no new type, but instead new functionality in the JuliaParser.parse() function.
In my case, my package which I will eventually submit is called AcceleratorLattice.jl. There is no AcceleratorLattice type but there is a Lattice type. So should I be calling my package AcceleratorLattices.jl or does it matter?
Maybe plural should be used if the main Type/structure is expected to have many instances in an application, and singular if the main Type/structure is expected to be a singleton.
Hard to say in the abstract, but having glanced at the documentation linked from your README, I would indeed lean towards the pluralized AcceleratorLattices being the more Julian name