docs: update README.md

README.md

@@ -20,34 +20,34 @@ The project consists of the following classes and interfaces:
 
 ### Class Diagram
 ```plaintext
-+-------------------+
+       +-------------------+               +-------------------+
-|      Vehicle      |
+       |      Vehicle      |               |    Serviceable    |
-| (Abstract Class)  |
+       | (Abstract Class)  |               |    (Interface)    |
-+-------------------+ -----------------+-----------------+--------+
+       +-------------------+               +-------------------+
-^                                                                 |
+                 ^                                   ^
-| extends                                                         |
+                 | extends                           | implements
-|                                   +-------------------+         |
+                 |                                   |
-|                                   |    Serviceable    | <-------+
+                 +-----------------------------------+
-|                                   |    (Interface)    | implements
+                                   |
-|                                   +-------------------+         
+                         +-------------------+
-+-------------------+
+                         |        Car        |
-|        Car        |
+                         | (Abstract Class)  |
-| (Abstract Class)  |
+                         +-------------------+
-+-------------------+
+                                   ^
-^
+                                   | extends
-| extends
+                 +-----------------+-----------------+
-+-----------------+-----------------+
+                 |                                   |
-|                                   |
+       +-------------------+               +-------------------+
-  +-------------------+               +-------------------+
+       |      GasCar       |               |    ElectricCar    |
-  |      GasCar       |               |    ElectricCar    |
+       |      (Class)      |               |      (Class)      |
-  |      (Class)      |               |      (Class)      |
+       +-------------------+               +-------------------+
-  +-------------------+               +-------------------+
+         ^               ^                                   ^
-^
+         | extends       | implements                        | implements
-| extends
+         |               |                                   |
-  +-------------------+
++-------------------+  +-------------------+       +-------------------+
-  |     SportsCar     |
+|     SportsCar     |  |    Refuelable     |       |    Chargeable     |
-  |      (Class)      |
+|      (Class)      |  |    (Interface)    |       |    (Interface)    |
-  +-------------------+
++-------------------+  +-------------------+       +-------------------+
 ```
 
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