Bundler: Generate gem skeleton with Rust extension

Do you think dynamically typed interpreted Ruby language and statically typed compiled Rust language could be friends? Yes, they can! And actually, they are!Officially it all started when YJIT was ported to Rust and Ruby codebase has officially onboarded Rust code. This friendship matured when RubyGems 3.3.11 (with a new Add cargo builder for rust extensions feature) was released capable of compiling Rust-based extensions during gem installation process (similar to well-known C-based gem extensions like nokogiri, pg or puma).