added count down timer

src/components/countdown/CustomTimer.jsx

@@ -0,0 +1,24 @@
+import React, { useEffect, useState } from 'react'
+
+export default function CustomTimer({className='text-emerald-500'}) {
+
+    const [time, setTime] = useState(Number(process.env.REACT_APP_CUSTOMTIMER))
+
+    useEffect(()=>{
+        const timer = setInterval(()=>{
+            setTime(prev => prev - 1)
+        },1000)
+        return ()=>{
+            clearInterval(timer)
+        }
+    },[])
+
+    let minutes = Math.floor(time/60)
+    let seconds = time - (minutes * 60)
+
+  return (
+    <p className={`w-full text-base text-emerald-500 ${className}`}>
+        {`${minutes > 9 ? minutes : '0'+minutes} : ${seconds > 9 ? seconds : '0'+seconds}`}
+    </p>
+  )
+}