Pullbug

- Adds `--disable_descriptions` flag which will not populate the description in messages

- Adds support for team reviewers to populate in messages

- Adds `log_level` flag allowing the user to specify a log level of their choice (defaults to `INFO`)

- Filters out pull requests from the returned issues. Apparently GitHub's v3 API returns pull requests in the response of a list of issues, see <https://docs.github.com/en/rest/reference/issues#list-repository-issues> for details

- Messages now include dismissed reviewers under the `Reviewers` section
- Reviewers are now a set to avoid duplicates (such as multiple "changes requested" or "dismissed" reviews)

- Adds reviewers to messages who have approved or requested changes. Previously, only reviewers that had been requested but had not reviewed would show in messages. Depending on the status of the review, an appropriate emoji will show in the message to signify what the user did for their review
- Various other small improvements to message building