created timelineData function and added it to its route

src/api/timelineData.php

@@ -1,7 +1,25 @@
 <?php
-
+require_once "./confjg.php"
 
 class TimelineData
 {
+    function getTimelineData()
+    {
+        $conn = dbConn();
+        $stmt = $conn->prepare("SELECT * FROM timeline;"); 
+        $stmt->execute();
 
+        // set the resulting array to associative
+        $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
+        
+        if ($result)
+        {
+            return $result;
+        }
+        else 
+        {
+            return array("errorMessage" => "Error timeline data not found");
+        }
+          
+    }
 }