Fixes #26

Current Features-

1. The main screen is having floating button as route to chat screen(attached screenshot)
2. On the chat screen, whenever someone sends a text message, his/her email id(as displayname is not available) is being displayed along with the time ago(attached video below)
3. These text messages are being stored in the "messages" collection in cloud firestore where each message has a unique document id with the collection of a) author b) content c) time
4. Now, the stored messages are being fetched in decreasing order of their time.

Bugs that need to be fixed:

1. When scrolling is required, then the current message is not displayed in time after sending and comes up after another msg is sent (attached video demo)
2. Chats need to be started from the end of the page having recent chats like other messaging apps