Update index with join information

pages/index.md

@@ -3,6 +3,8 @@ title = ""
 id = "home"
 pageHeader = "Join the Band!"
 summary = "Are you a Brown University undergraduate, grad student, or employee? Does your heart swell with pride whenever a touchdown, basket, or goal is scored in defense of Brunonia’s honor? Do your friends refuse to attend sporting events with you because they are embarrassed by your loud and heartfelt cheering? Do you like bagels? If yes, you’re already Brown Band material - all you have to do now is join up!"
+
+The band's first rehearsal will be Tuesday, September 12th at 6:00pm in Fulton Rehearsal Hall. It will be preceded by an ice cream social at 5:00pm. We would love to have you there! To join our mailing list, use [this link](https://docs.google.com/forms/d/e/1FAIpQLScJHkNFJ3TO91DiLW8Md36x8BRHqXWUfHYPrZc31fnJA36SIQ/viewform).
 +++
 
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