added palindrome.js to Algorithms

Algorithms/Javascript/palindrome.js

@@ -0,0 +1,19 @@
+//determines whether a word is a palindrome or not
+const isPalindrome = function (word) {
+  let arr = [];
+
+  //loops through word in reverse, then pushes to array
+  for (let i = word.length - 1; i >= 0; i--) {
+    arr.push(word[i]);
+  }
+
+  // combines the arr
+  let newWord = arr.join("");
+
+  // compares word with newWord, if they match true is returned else false is returned
+  if (word == newWord) {
+    return true;
+  } else {
+    return false;
+  }
+};