Fix README.md

[mza79]

• Screensharing ->Screen Sharing
• allow user -> allow users
• realtime -> real time
• Hopefully this will make it more convenient -> This project will make information sharing more convenient
• We hope to eliminate -> We aim to eliminate
• tedious cycle of first using the camera app to take pictures of our ideas, uploading and sending them through a second app, and opening yet another app to flesh out the ideas over video chat.
  -> tedious cycle of first taking pictures of our ideas with the camera app, then uploading and sending them through a second app and opening yet another app to flesh out the ideas over video chat

Fix #3