docs: Declare build-rs as intentional

crates/build-rs/README.md

@@ -0,0 +1,2 @@
+> This crate is maintained by the Cargo team for use by the wider
+> ecosystem. This crate follows semver compatibility for its APIs.

crates/build-rs/src/lib.rs

@@ -1,6 +1,9 @@
 //! build-rs provides a strongly typed interface around the Cargo build script
 //! protocol. Cargo provides inputs to the build script by environment variable
 //! and accepts commands by printing to stdout.
+//!
+//! > This crate is maintained by the Cargo team for use by the wider
+//! > ecosystem. This crate follows semver compatibility for its APIs.
 #![cfg_attr(all(doc, feature = "unstable"), feature(doc_auto_cfg, doc_cfg))]
 #![allow(clippy::disallowed_methods)] // HACK: deferred resoling this
 #![allow(clippy::print_stdout)] // HACK: deferred resoling this

src/doc/contrib/src/team.md

@@ -170,6 +170,7 @@ The degree of process is correlated with the degree of change being proposed:
 
 Per the [Rust crate ownership policy](https://forge.rust-lang.org/policies/crate-ownership.html), the Cargo team's "Intentional Artifacts" include:
 
+- [build-rs](https://crates.io/crates/build-rs)
 - [cargo-credential](https://crates.io/crates/cargo-credential)
 - [cargo-platform](https://crates.io/crates/cargo-platform)
 - [cargo-util-schemas](https://crates.io/crates/cargo-util-schemas)