Add nuget package

On install, the package:
- Adds InjectModuleInitializer.exe to the nuget package's 'tools' folder.
- Adds a `AfterBuild` target to the project.
   - Uses the "default" command-line arguments.
     - Not signed.
     - Default file/method name.
- Adds a ModuleInitializer class (per the default command-line args above), to the project root.
   - Includes *// TODO: Add assembly initialization logic* comment to indicate to the user where to put their module initialization logic.
- Displays a README, including *TODO:* and *License* sections.

On uninstall, the package:
- Removes the project's `AfterBuild` target.