(googledrive) Add releaseNotes URL

Description

This changeset adds googledrive's release notes URL, as published and maintained by Google, to the package's metadata.

Motivation and Context

Fairly self-explanatory change. Adding the releaseNotes tag with the URL to the Nuspec, to ensure it's readily available from the package page on the Community Repository.

How Has this Been Tested?

choco packed with the modified Nuspec.

Opened the resulting package with NuGet Package Explorer, and confirmed the Release Notes section populates as expected.

Screenshot (if appropriate, usually isn't needed):

N/A

Types of changes

[ ] Bug fix (non-breaking change which fixes an issue)
[x] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to change)
[ ] Migrated package (a package has been migrated from another repository)

Checklist:

[x] My code follows the code style of this repository.
[ ] My change requires a change to documentation (this usually means the notes in the description of a package).
[ ] I have updated the documentation accordingly (this usually means the notes in the description of a package).
[ ] I have updated the package description and it is less than 4000 characters.
[x] All files are up to date with the latest Contributing Guidelines
[x] The added/modified package passed install/uninstall in the chocolatey test environment.
[x] The changes only affect a single package (not including meta package).

mkevenaar / chocolatey-packages

(googledrive) Add releaseNotes URL #183