[fp-rs] Initial Rust dummy commit for Flutter UI demo

fastpair/rust/demo/rust/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "rust"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+crate-type = ["lib", "cdylib", "staticlib"]
+
+[dependencies]
+flutter_rust_bridge = "1"

fastpair/rust/demo/rust/src/api.rs

@@ -0,0 +1,3 @@
+pub fn hello() -> String {
+    String::from("Rust says hi!")
+}

fastpair/rust/demo/rust/src/lib.rs

@@ -0,0 +1 @@
+mod api;