Add .gitignore file

[maksrom]

Hi @averemi ,

I've found a small problem with project size that would be great to fix to decrease cloning time and see the difference between commits in a better way.
To resolve this issue .gitignore file should be in a root dir of a project. See details: https://www.atlassian.com/git/tutorials/saving-changes/gitignore

Just 2 steps:

• remove unnecessary all files
• create a file named ".gitignore" that contains code below:

Flash Chat.xcworkspace/
Flash Chat.xcodeproj/
Pods/

Please, correct me if I missed something. Here is a link with enterprise file for Swift project if you don't want to care about details: https://github.com/github/gitignore/blob/master/Swift.gitignore

Waiting for your response,
Max