wide-mul is a crate feature

here goes another bottom-up rewrite

fixed_wide/Cargo.toml

@@ -4,8 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [features]
-default=["zeroes"]
+default=["zeroes","wide-mul"]
 ratio=[]
+wide-mul=[]
 zeroes=["ratio","dep:arrayvec"]
 
 [dependencies]

fixed_wide/src/fixed.rs

@@ -1,6 +1,7 @@
 use bnum::{BInt,cast::As};
 
 #[derive(Clone,Copy,Debug,Hash)]
+/// A Fixed point number for which multiply operations widen the bits in the output. (when the wide-mul feature is enabled)
 /// N is the number of u64s to use
 /// F is the number of fractional bits (always N*32 lol)
 pub struct Fixed<const N:usize,const F:usize>{