chore: fix metadata

Cargo.toml

@@ -12,9 +12,12 @@ categories = ["data-structures", "parsing"]
 
 # rust-version = "1.51.0" # The first version of Cargo that supports this field is 1.56.0
 
-[metadata]
+[package.metadata]
 msrv = "1.51.0"
 
+[package.metadata.docs.rs]
+all-features = true
+
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [features]