Add segmentio menu library

[cihannakgul]

• Project Name: SegmentIO
• Project URL: https://github.com/Yalantis/Segmentio
• Project Description: Animated top/bottom segmented menu for iOS
• Why it should be added to awesome-swift: I use SegmentIO for creating animated native menus in personal and professional projects, and it works smoothly and efficiently. It is constantly updated and supports Auto-Layout. It's one of the most successful libraries I've come across, and I wanted it to be included in this guide so that people can benefit from it
• At least 15 stars (GitHub project)
• Support Swift 5
• Updated contents.json instead of README
• Lib is fully open sourced, written in Swift and not a wrapper over compiled lib
• Description does not say "written in Swift" or variant 🤓

[vpeschenkov]

thx 👍