Switch mdbook-spec to build with release

This should speed things up a little, particularly when working locally.

Author: ehuss

book.toml

@@ -18,7 +18,7 @@ smart-punctuation = true
 edition = "2021"
 
 [preprocessor.spec]
-command = "cargo run --manifest-path mdbook-spec/Cargo.toml"
+command = "cargo run --release --manifest-path mdbook-spec/Cargo.toml"
 
 [build]
 extra-watch-dirs = ["mdbook-spec/src"]