Register Julia PDK (Botched)

[wildart]

A wonderful package that could publish itself.

[jakebolewski]

I think all the docstrings that got removed should be added to the package.

[wildart]

I moved docstrings from helpdb.jl to PkgDev.jl for related functions.

[hayd]

Note the error:

ERROR: LoadError: AssertionError: Invalid url scheme https for package PkgDev. Should be 'git' 

Presumably the docs for package development are going remain in the main julia lang docs?

[wildart]

For the new package manager all packages would be registered with https protocol, git+ssh will be dropped. Because the nightly version is shipped with libgit2 library that is built without support of ssh protocol.

[wildart]

Messed it up. See #3628