installable_on_version doesn't set .server_type, .api_url

[mortenpi]

This makes DocumentationGenerator.build_documentation fail with

ERROR: type NamedTuple has no field server_type
Stacktrace:
 [1] getproperty
   @ ./Base.jl:38 [inlined]
 [2] start_builder(package::NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}, version::VersionNumber; basepath::String, juliacmd::String, registry_path::String, deployment_url::String, update_only::Bool, src_prefix::Nothing, href_prefix::Nothing, timeout::Int64, max_timeout::Int64, kill_timeout::Int64)
   @ DocumentationGenerator ~/jc/docgen/dev/DocumentationGenerator/src/DocumentationGenerator.jl:271
 [3] (::DocumentationGenerator.var"#74#75"{Int64, Float64, String, String, typeof(last), String, Bool, Int64, Int64, Int64, Vector{NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}}, Vector{Any}, String})()
   @ DocumentationGenerator ~/jc/docgen/dev/DocumentationGenerator/src/DocumentationGenerator.jl:126
 [4] withenv(f::DocumentationGenerator.var"#74#75"{Int64, Float64, String, String, typeof(last), String, Bool, Int64, Int64, Int64, Vector{NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}}, Vector{Any}, String})
   @ Base ./env.jl:179
 [5] build_documentation(packages::Vector{NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}}; processes::Int64, sleeptime::Float64, juliacmd::String, basepath::String, envpath::String, filter_versions::typeof(last), sync_registry::Bool, deployment_url::String, update_only::Bool, registry::String, timeout::Int64, max_timeout::Int64, kill_timeout::Int64)
   @ DocumentationGenerator ~/jc/docgen/dev/DocumentationGenerator/src/DocumentationGenerator.jl:116
 [6] build_documentation(packages::Vector{NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}})
   @ DocumentationGenerator ~/jc/docgen/dev/DocumentationGenerator/src/DocumentationGenerator.jl:73
 [7] top-level scope
   @ ~/jc/docgen/mwe.jl:10

For an MWE

using DocumentationGenerator
pkgs = DocumentationGenerator.installable_on_version(VERSION)
pkg = let pkgs = collect(pkgs)
    i = findfirst(kv -> kv.second.name == "MarkdownAST", pkgs)
    pkgs[i].second
end
DocumentationGenerator.build_documentation([pkg])

From #186 I think, cc @vdayanand

[mortenpi]

Just noticed that this also breaks the documented ./run/makedocs.jl script:

$ julia --project run/makedocs.jl
┌ Warning: No `xvfb` installed. Running without it.
└ @ DocumentationGenerator ~/juliadocs/clones/DocumentationGenerator.jl/src/DocumentationGenerator.jl:92
Cloning into '/tmp/jl_131yoo/registry'...
remote: Enumerating objects: 14, done.
remote: Counting objects: 100% (14/14), done.
remote: Compressing objects: 100% (11/11), done.
remote: Total 14 (delta 0), reused 7 (delta 0), pack-reused 0
Receiving objects: 100% (14/14), 7.75 KiB | 7.75 MiB/s, done.
    Updating registry at `~/.julia/registries/General.toml`
ERROR: LoadError: type NamedTuple has no field server_type
Stacktrace:
 [1] getproperty
   @ ./Base.jl:37 [inlined]
 [2] start_builder(package::NamedTuple{(:name, :url, :uuid, :path, :versions), Tuple{String, String, String, String, Vector{VersionNumber}}}, version::VersionNumber; basepath::String, juliacmd::String, registry_path::String, deployment_url::String, update_only::Bool, src_prefix::Nothing, href_prefix::Nothing, timeout::Int64, max_timeout::Int64, kill_timeout::Int64)
   @ DocumentationGenerator ~/juliadocs/clones/DocumentationGenerator.jl/src/DocumentationGenerator.jl:270
 [3] (::DocumentationGenerator.var"#74#75"{Int64, Float64, String, String, typeof(last), String, Bool, Int64, Int64, Int64, Vector{Any}, Vector{Any}, String})()
   @ DocumentationGenerator ~/juliadocs/clones/DocumentationGenerator.jl/src/DocumentationGenerator.jl:125
 [4] withenv(f::DocumentationGenerator.var"#74#75"{Int64, Float64, String, String, typeof(last), String, Bool, Int64, Int64, Int64, Vector{Any}, Vector{Any}, String})
   @ Base ./env.jl:204
 [5] build_documentation(packages::Vector{Any}; processes::Int64, sleeptime::Float64, juliacmd::String, basepath::String, envpath::String, filter_versions::typeof(last), sync_registry::Bool, deployment_url::String, update_only::Bool, registry::String, timeout::Int64, max_timeout::Int64, kill_timeout::Int64)
   @ DocumentationGenerator ~/juliadocs/clones/DocumentationGenerator.jl/src/DocumentationGenerator.jl:115
 [6] top-level scope
   @ ~/juliadocs/clones/DocumentationGenerator.jl/run/makedocs.jl:15
in expression starting at /home/mortenpi/juliadocs/clones/DocumentationGenerator.jl/run/makedocs.jl:15