[swiftlint] Fix: MARK comment should be in valid format.

Author: jawwad

Ternary Search Tree/TST.playground/Sources/TernarySearchTree.swift

@@ -15,7 +15,7 @@ public class TernarySearchTree<Element> {
 
     public init() {}
 
-    //MARK: - Insertion
+    // MARK: - Insertion
 
     public func insert(data: Element, withKey key: String) -> Bool {
         return insert(node: &root, withData: data, andKey: key, atIndex: 0)
@@ -59,7 +59,7 @@ public class TernarySearchTree<Element> {
     }
 
 
-    //MARK: - Finding
+    // MARK: - Finding
 
 
     public func find(key: String) -> Element? {

Ternary Search Tree/TernarySearchTree.swift

@@ -23,7 +23,7 @@ public class TernarySearchTree<Element> {
      */
     public init() {}
 
-    //MARK: - Insertion
+    // MARK: - Insertion
 
     /**
     Public insertion method.
@@ -85,7 +85,7 @@ public class TernarySearchTree<Element> {
     }
 
 
-    //MARK: - Finding
+    // MARK: - Finding
 
     /**
     Public find method.