🔧 chore(Cargo): configure project settings and lints

- add clippy lints for format args and unnecessary semicolon warnings
- allow rust dead-code lint temporarily for development phase
- specify library and binary paths for project structure

src/lib.rs

@@ -1,14 +1,5 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![warn(missing_docs)]
+#![cfg_attr(docsrs, feature(rustdoc_missing_doc_code_examples))]
+#![cfg_attr(docsrs, warn(rustdoc::invalid_codeblock_attributes))]
+#![doc = include_str!("../docs/lib.md")]