Static assert printf format

[SiebrenW]

The main advantages of this library in the format mode to me is the compile time check for the validity of the format.

Coming from a codebase with a printf style logger I extended it to use fmt for the above benefits, but had to keep a legacy log function around for the old code. The problem is that people aren't using the new one and are still making mistakes in the format of the printf-style log function.

Is it desired to add this static assert check to this library in the printf functions? For us, that would save us some iterations due to some formatting error crashing the program in testing (preferably it saying: "you messed up the printf format, and you should be using fmt anyways!").

For illustration purposes here's a godbolt link: https://godbolt.org/z/c6sa35635