feat: create lib and cli with a simple reference to start working

src/cli.rs

@@ -0,0 +1,5 @@
+use clockcalclib::test;
+
+pub fn main() {
+    test();
+}

src/lib.rs

@@ -0,0 +1,11 @@
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}
+
+pub fn test() {
+    println!("This lib seems to work!");
+}