Fix Contribution (#27)

Author: kassane

CONTRIBUTING.md

@@ -71,8 +71,8 @@ if (std.mem.eql(u8, op, "category/algorithm-name"))
 to test add:
 
 ```zig
-# runall.zig
+// runall.zig
 try runTest(allocator, "category/algorithm-name");
 ```
 
-**Note:** Do not change or modify the files (`build.zig` & `runall.zig`) without first suggesting it to the maintainers (open/issue proposal).
+**Note:** Do not change or modify the files (`build.zig` & `runall.zig`) without first suggesting it to the maintainers (open/issue proposal).

DIRECTORY.md

@@ -16,6 +16,9 @@
   * [Knapsack](https://github.com/TheAlgorithms/Zig/blob/HEAD/dynamicProgramming/knapsack.zig)
   * [Longestincreasingsubsequence](https://github.com/TheAlgorithms/Zig/blob/HEAD/dynamicProgramming/longestIncreasingSubsequence.zig)
 
+## Machine Learning
+  * [K Means Clustering](https://github.com/TheAlgorithms/Zig/blob/HEAD/machine_learning/k_means_clustering.zig)
+
 ## Math
   * [Ceil](https://github.com/TheAlgorithms/Zig/blob/HEAD/math/ceil.zig)
   * [Chineseremaindertheorem](https://github.com/TheAlgorithms/Zig/blob/HEAD/math/chineseRemainderTheorem.zig)
@@ -25,6 +28,8 @@
   * [Gcd](https://github.com/TheAlgorithms/Zig/blob/HEAD/math/gcd.zig)
   * [Primes](https://github.com/TheAlgorithms/Zig/blob/HEAD/math/primes.zig)
 
+## [Runall](https://github.com/TheAlgorithms/Zig/blob/HEAD//runall.zig)
+
 ## Search
   * [Binarysearchtree](https://github.com/TheAlgorithms/Zig/blob/HEAD/search/binarySearchTree.zig)
   * [Redblacktrees](https://github.com/TheAlgorithms/Zig/blob/HEAD/search/redBlackTrees.zig)