feat: add php solution to lc problem: No.1984 (#1074)

Author: Qiu-IT

solution/1900-1999/1984.Minimum Difference Between Highest and Lowest of K Scores/README.md

@@ -146,6 +146,26 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @param Integer $k
+     * @return Integer
+     */
+    function minimumDifference($nums, $k) {
+        sort($nums);
+        $rs = 10 ** 5;
+        for ($i = 0; $i < count($nums) - $k + 1; $i++) {
+            $rs = min($rs, $nums[$i + $k - 1] - $nums[$i]);
+        }
+        return $rs;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1900-1999/1984.Minimum Difference Between Highest and Lowest of K Scores/README_EN.md

@@ -136,6 +136,26 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @param Integer $k
+     * @return Integer
+     */
+    function minimumDifference($nums, $k) {
+        sort($nums);
+        $rs = 10 ** 5;
+        for ($i = 0; $i < count($nums) - $k + 1; $i++) {
+            $rs = min($rs, $nums[$i + $k - 1] - $nums[$i]);
+        }
+        return $rs;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1900-1999/1984.Minimum Difference Between Highest and Lowest of K Scores/Solution.php

@@ -0,0 +1,15 @@
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @param Integer $k
+     * @return Integer
+     */
+    function minimumDifference($nums, $k) {
+        sort($nums);
+        $rs = 10 ** 5;
+        for ($i = 0; $i < count($nums) - $k + 1; $i++) {
+            $rs = min($rs, $nums[$i + $k - 1] - $nums[$i]);
+        }
+        return $rs;
+    }
+}