Increased the popup width to fix a UI bug

Updates for the copy/send PR message feature
• Support for graphite URL's in the PR message template
• Support for markdown links in the PR message template

Version 1.1 Release Notes
- New feature - copy or send PR messages to Slack from GitHub or Graphite!
- Minor bug fixes

In the Slacky settings page, you can add a list of Slack channels that you want to send pull request links to. On GitHub and Graphite, you'll see a new button to copy a custom PR message, or send the message automatically to a specific Slack channel that you added. You can also use a custom format for your PR message.