test fixed-macro rustdoc example

Cargo.toml

@@ -34,6 +34,7 @@ num-traits = { version = "0.2.12", default-features = false, optional = true }
 serde = { version = "1.0.60", default-features = false, optional = true }
 
 [dev-dependencies]
+fixed-macro = "1"
 rand = { version = "0.7", default-features = false }
 rand_xoshiro = "0.4"
 criterion = "0.3"

src/lib.rs

@@ -145,7 +145,7 @@ cannot use [`From`] as we have less fractional bits, so we use
 The [*fixed-macro* crate] provides a convenient macro to write down
 fixed-point constants literally in the code.
 
-```ignore
+```rust
 use fixed::types::I16F16;
 use fixed_macro::fixed;