fix(release): restrict published package to src + manifest

The specs/ corpus (127 MB of real-world OpenAPI documents) is tracked in
git and was being bundled into the crate, pushing the tarball past
crates.io's 10 MiB upload limit (413 Payload Too Large on v0.5.0).

Add an include allowlist so only src/, Cargo.toml, README, and LICENSE
ship. Packaged size drops to ~900 KiB (188 KiB compressed).

Author: lightsofapollo

Cargo.toml

@@ -11,6 +11,12 @@ homepage = "https://github.com/gpu-cli/openapi-to-rust"
 keywords = ["openapi", "codegen", "rust", "sse", "api-client"]
 categories = ["development-tools", "web-programming"]
 readme = "README.md"
+include = [
+    "/src/**",
+    "/Cargo.toml",
+    "/README.md",
+    "/LICENSE",
+]
 
 [dependencies]
 clap = { version = "4.5", features = ["derive"] }