Updated README.md (aimacode#771)

* Update README.md

Author: ad71

README.md

@@ -40,7 +40,7 @@ Here is a table of algorithms, the figure, name of the algorithm in the book and
 | 2.10   | Simple-Reflex-Agent               | `SimpleReflexAgent`           | [`agents.py`][agents]           |      | Included         |
 | 2.12   | Model-Based-Reflex-Agent          | `ReflexAgentWithState`        | [`agents.py`][agents]           |      | Included         |
 | 3      | Problem                           | `Problem`                     | [`search.py`][search]           | Done |          |
-| 3      | Node                              | `Node`                        | [`search.py`][search]           | Done |          |
+| 3      | Node                              | `Node`                        | [`search.py`][search]           | Done | Included |
 | 3      | Queue                             | `Queue`                       | [`utils.py`][utils]             | Done | No Need       |
 | 3.1    | Simple-Problem-Solving-Agent      | `SimpleProblemSolvingAgent`   | [`search.py`][search]           |      | Included         |
 | 3.2    | Romania                           | `romania`                     | [`search.py`][search]           | Done | Included |
@@ -105,7 +105,7 @@ Here is a table of algorithms, the figure, name of the algorithm in the book and
 | 15.17  | Particle-Filtering                | `particle_filtering`          | [`probability.py`][probability] | Done |          |
 | 16.9   | Information-Gathering-Agent       |                               |                                 |      |          |
 | 17.4   | Value-Iteration                   | `value_iteration`             | [`mdp.py`][mdp]                 | Done | Included |
-| 17.7   | Policy-Iteration                  | `policy_iteration`            | [`mdp.py`][mdp]                 | Done |          |
+| 17.7   | Policy-Iteration                  | `policy_iteration`            | [`mdp.py`][mdp]                 | Done | Included |
 | 17.9   | POMDP-Value-Iteration             |                               |                                 |      |          |
 | 18.5   | Decision-Tree-Learning            | `DecisionTreeLearner`         | [`learning.py`][learning]       | Done | Included |
 | 18.8   | Cross-Validation                  | `cross_validation`            | [`learning.py`][learning]       |      |          |