Add Chocolatey package.

[malcyon]

Add files for Chocolatey package.

Tested with:
https://github.com/chocolatey-community/chocolatey-test-environment

Once this PR is merged, I will release 1.1.0 of the sidecar, then I'll publish the Chocolatey package.

[malcyon]

@mpfz0r Before I release 1.0.3 of the Sidecar, does the documentation need to be updated to show the minimim Graylog server compatible with Beats >7.0?

#391

[mpfz0r]

@mpfz0r Before I release 1.0.3 of the Sidecar, does the documentation need to be updated to show the minimim Graylog server compatible with Beats >7.0?

#391

I guess so. They need to be running Graylog 3.2.5 or newer

[mpfz0r]

speaking of a new release: have you seen #401

[malcyon]

speaking of a new release: have you seen #401

I saw it. I haven't used Go enough to understand the scope. I can go read up on it and try to get it done, though! Gives me a chance to use it.

[mpfz0r]

A few smaller things. Rest looks good, from what I can tell.