feat(scaffolding): add Rust package generator

tools/scaffolding/templates/BUILD.template

@@ -0,0 +1,26 @@
+load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_library", "rust_test")
+
+rust_library(
+  name = "{CRATE_NAME}",
+  crate_name = "{CRATE_NAME}",
+  srcs = [
+    "{CRATE_NAME}.rs",
+    "{CRATE_NAME}_test.rs",
+  ],
+)
+
+rust_test(
+  name = "{CRATE_NAME}_test",
+  crate = ":{CRATE_NAME}",
+)
+
+rust_binary(
+  name = "{CRATE_NAME}_cli",
+  crate_name = "{CRATE_NAME}_cli",
+  srcs = [
+    "{CRATE_NAME}_main.rs",
+  ],
+  deps = [
+    ":{CRATE_NAME}",
+  ],
+)