3.0.0

• This library now requires .NET Framework 4.6.1 or greater or .NET Standard
  2.0 or greater.
• .NET 5.0 was added as a target framework.
• When decoding strings in a memory-mapped file, the reader no longer
  allocates a temporary byte[]. This significantly improves performance but
  requires the use of unsafe code.
• FileAccessMode.MemoryMapped now works if the database path specified is
  a symbolic link to the actual database.