Clean up Pubspec and Podspec metadata

[Nash0x7E2]

Description

This PR cleans up the description, package information, and author information for battery_plus_macos.

Related Issues

• None

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]).
This will ensure a smooth and quick review process. Updating the pubspec.yaml and changelogs is not required.

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See [Contributor Guide]).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (flutter analyze) does not report any problems on my PR.
• I read and followed the [Flutter Style Guide].
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

• No, this is not a breaking change.