Compile-time name trimming and binary size

[Christian-Sander]

I've added better-enums to an embedded project with limited binary size.
After converting a single existing enum to BETTER_ENUM the binary size increased by ~5 kB which is not acceptable for such a project.
I was able to trim this to less than 1 kB by enabling the compile-time name trimming feature so it seems that the runtime code is pulling in many dependencies or generating much code.

In such a case using the compile-time name trimming feature is definitely preferred, so I suggest to add a small note about that to the documentation for other users.