(autohotkey.install) add to to description about virus positives

[TheCakeIsNaOH]

Description

Adds a note about the high virus count to the description of the package, copied from autohotkey.portable

Motivation and Context

The package currently has a high virus count, and cannot be exempted as it does not have the note in the package description like the .portable package has.

Related issue #2187

How Has this Been Tested?

Ran update script and ensured that nuspec was updated correctly.

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

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• 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:

• 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.
• All files are up to date with the latest Contributing Guidelines
• The added/modified package passed install/uninstall in the Chocolatey Test Environment(https://github.com/chocolatey-community/chocolatey-test-environment/). Note that we don't support the use of any other environment.
• The changes only affect a single package (not including meta package).

[AppVeyorBot]

✅ Package verification completed without issues. PR is now pending human review

[pauby]

Thanks for adding that @TheCakeIsNaOH!