Allows Serialization for System.Numerics.BigInteger
Allows you to save data into a string and BigInteger will parse that string's data, so you can save and load serializable BigInteger data
Mainly wrote for UnityEngine but can be used for other projects
Example: Test/TestCustomBigInteger.cs
No special setup. Just add the file CustomBigInteger.cs to your project(s) and call "CustomBigInteger" as a variable, etc.