add Aptabase

[goenning]

• Project Name: Aptabase
• Project URL: https://github.com/aptabase/aptabase
• Project Description: Open Source, Privacy-First and Simple Analytics for Swift Apps
• Why it should be added to awesome-swift: Swift is the top 1 most used SDK in Aptabase so I figured Swift devs must like the focus on being lightweight and simple. The repo linked above is the main repository, the SDK is in aptabase/aptabase-swift
• 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 👍