feat: add php solution to lc problem: No.1480 (doocs#986)

Author: Qiu-IT

solution/1400-1499/1480.Running Sum of 1d Array/README.md

@@ -95,6 +95,22 @@ func runningSum(nums []int) []int {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer[]
+     */
+    function runningSum($nums) {
+        for ($i = 1; $i < count($nums); $i++)
+            $nums[$i] += $nums[$i - 1];
+        return $nums;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1400-1499/1480.Running Sum of 1d Array/README_EN.md

@@ -100,6 +100,22 @@ func runningSum(nums []int) []int {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer[]
+     */
+    function runningSum($nums) {
+        for ($i = 1; $i < count($nums); $i++)
+            $nums[$i] += $nums[$i - 1];
+        return $nums;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1400-1499/1480.Running Sum of 1d Array/Solution.php

@@ -0,0 +1,11 @@
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer[]
+     */
+    function runningSum($nums) {
+        for ($i = 1; $i < count($nums); $i++)
+            $nums[$i] += $nums[$i - 1];
+        return $nums;
+    }
+}