Add bin using crate cron_job.

src/bin/using-crate-cron_job.rs

@@ -0,0 +1,32 @@
+use cron_job::{CronJob, Job};
+
+fn main() {
+    // Create HelloJob
+    let hello_job = HelloJob {
+        name: "John".into(),
+    };
+    // Create CronJob
+    let mut cron = CronJob::default();
+    // Run function every second
+    cron.new_job("* * * * * *", run_every_second);
+    // Say hello every second
+    cron.new_job("* * * * * *", hello_job);
+    // Start jobs
+    cron.start().expect("Failed start jobs.");
+}
+// The function to be executed every second.
+fn run_every_second() {
+    println!("1 second");
+}
+
+// The job to be executed
+struct HelloJob {
+    name: String,
+}
+
+// Very important, implement the Job trait and its functions.
+impl Job for HelloJob {
+    fn run(&mut self) {
+        println!("Hello, {}!", self.name);
+    }
+}