Add a "Go to Github" button on Graphite PRs
目前為 2023-01-16 提交的版本，檢視 最新版本。
這裡只顯示彼此間有代碼差異的版本。 顯示所有版本。
If the toolbar already exists, add the button immediately
Run on document-idle, not document-start. This should help the button appear more reliably by waiting a bit longer for the page to load all elements.
- update styling to work in dark mode (steal styling from 'Review changes' button)
- match their new URL: app.graphite.com- update matching regex to handle dash (-) in repo or project name (thanks @gaosong2101!)
Fixes issue where the button might show twice
