[3] add hash table

pomelovsd/HashTable.py

@@ -0,0 +1,3 @@
+def 
+
+def ht_insert(buckets, name, phone):

pomelovsd/data_structures.ipynb

@@ -15,7 +15,8 @@
     }
    ],
    "source": [
-    " "
+    "import LinkedLists\n",
+    "import HashTable\n"
    ]
   }
  ],