fix: markdown according to the rules

Author: masiljangajji

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,8 +2,6 @@
 
 <!-- Your content goes here: -->
 
-
-
 <!-- DO NOT EDIT BELOW THIS LINE! -->
 ---
 

exercises/practice/parallel-letter-frequency/.approaches/fork-join/content.md

@@ -1,4 +1,4 @@
-# `Fork/Join` 
+# `Fork/Join`
 
 ```java
 import java.util.Map;
@@ -11,7 +11,7 @@ import java.util.concurrent.RecursiveTask;
 class ParallelLetterFrequency {
 
     List<String> texts;
-    ConcurrentMap<Character, Integer> letterCount;
+    ConcurrentMap<Character, Integer> letterCount; 
 
     ParallelLetterFrequency(String[] texts) {
         this.texts = List.of(texts);
@@ -82,8 +82,6 @@ Additionally, since uppercase and lowercase letters are treated as the same char
 
 After updating letter frequencies, the final map is returned.
 
-
-
 [ConcurrentHashMap]: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentHashMap.html
 [ForkJoinPool]: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ForkJoinPool.html
 [isAlphabetic]: https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#isAlphabetic-int-

exercises/practice/parallel-letter-frequency/.approaches/introduction.md

@@ -17,8 +17,7 @@ However, parallelStream() uses the common ForkJoinPool by default, meaning multi
 
 Although this doesn’t directly impact solving the Parallel Letter Frequency problem, it may introduce issues when thread pool sharing causes conflicts in other applications. Therefore, a custom ForkJoinPool approach is also provided below.
 
-
-## Approach: `parallelStream` 
+## Approach: `parallelStream`
 
 ```java
 import java.util.Map;

exercises/practice/parallel-letter-frequency/.approaches/parallel-stream/content.md

@@ -1,4 +1,4 @@
-# `parallelStream` 
+# `parallelStream`
 
 ```java
 import java.util.Map;
@@ -43,7 +43,5 @@ Since we treat uppercase and lowercase letters as the same character (e.g., A an
 
 After updating letter frequencies, the final map is returned.
 
-
-
 [ConcurrentHashMap]: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentHashMap.html
 [isAlphabetic]: https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#isAlphabetic-int-