contents: reorganize algorithms section

contents/algorithms/hash-table.md

@@ -8,3 +8,9 @@ title: Hash Table
 - Describe an implementation of a least-used cache, and big-O notation of it.
 - A question involving an API's integration with hash map where the buckets of hash map are made up of linked lists.
 - Implement data structure `Map` storing pairs of integers (key, value) and define following member functions in O(1) runtime: `void insert(key, value)`, `void delete(key)`, `int get(key)`, `int getRandomKey()`. [(Solution)](http://blog.gainlo.co/index.php/2016/08/14/uber-interview-question-map-implementation/)
+
+## Recommended courses
+
+import AlgorithmCourses from '../\_courses/AlgorithmCourses.md'
+
+<AlgorithmCourses />