Unable to install on Windows without git

> npm ERR! git clone https://github.com/documentjs/node-github-download undefined

On Windows systems it is common to install either the GitHub for Windows client or to use Git support integrated with Visual Studio. Neither scenario exposes a global commandline git client as is the standard with *nix-like OSes.

The whole point of using a package manager like NPM is to **actually install a package**. Why does the package installation attempt to use Git to clone the HEAD revision of the unstable master branch? This is **not** how you build a versioned, production-ready package.

I can understand taking a dependency on a Git commandline client **when actually documenting a release** present in a git repository, but leveraging Git to install the actual documentation framework itself is asinine. It locks out Windows users from using your tooling even if they would not need to go out to a remote repository to fetch documentation sources.

Start by inspecting the package dependencies and npm installation path to identify what pulls the unstable GitHub repository through git. Verify the package can be installed on Windows without a command-line git client and that the documentation source workflow still works; done means a versioned package installs through npm without that requirement.

Written by the indexing model from the issue text.