Add signpost on coreos/issue-sync once this tool is functional

[justaugustus]

Once this tool is further along, it would be good to drop a signpost issue on https://github.com/coreos/issue-sync to invite people to use/contribute to this fork in active development.

Must complete

• Add/update community health files #14

Nice to have

• Usage examples: Usage examples #6
• Document required token scopes: Document required token scopes #32
• Document dry-run operations: Document dry-run operations #36
• Add more informational messages to signal the start of functions #39

[justaugustus]

No longer possible, as the CoreOS origin repo has been archived.