zstd: hack include order to ensure that our zstd.h is found
If the regular Python CFLAGS include directories that already have the
zstd headers available, a different and possible incompatible version
can be picked up otherwise. Sadly, it seems like Python has no easy way
to prefix flags before the rest.
edition = "2018"
max_width = 79
wrap_comments = true
error_on_line_overflow = true