fix: corrected augmented assignment operations (#289)

pages/book/operators.mdx

@@ -607,42 +607,42 @@ let value: Int = 5;
 // +=
 value + 5;         // adds 5
 value = value + 5; // adds 5 and assigns result back
-value += value;    // also adds 5 and assigns result back
+value += 5;        // also adds 5 and assigns result back
 
 // -=
 value - 5;         // subtracts 5
 value = value - 5; // subtracts 5 and assigns result back
-value -= value;    // also subtracts 5 and assigns result back
+value -= 5;        // also subtracts 5 and assigns result back
 
 // *=
 value * 5;         // multiplies by 5
 value = value * 5; // multiplies by 5 and assigns result back
-value *= value;    // also multiplies by 5 and assigns result back
+value *= 5;        // also multiplies by 5 and assigns result back
 
 // /=
 value / 5;         // divides by 5
 value = value / 5; // divides by 5 and assigns result back
-value /= value;    // also divides by 5 and assigns result back
+value /= 5;        // also divides by 5 and assigns result back
 
 // %=
 value % 5;         // gets modulo by 5
 value = value % 5; // gets modulo by 5 and assigns result back
-value %= value;    // also gets modulo by 5 and assigns result back
+value %= 5;        // also gets modulo by 5 and assigns result back
 
 // &=
 value & 5;         // bitwise ANDs 5
 value = value & 5; // bitwise ANDs 5 and assigns result back
-value &= value;    // also bitwise ANDs 5 and assigns result back
+value &= 5;        // also bitwise ANDs 5 and assigns result back
 
 // ^=
 value ^ 5;         // bitwise XORs 5
 value = value ^ 5; // bitwise XORs 5 and assigns result back
-value ^= value;    // also bitwise XORs 5 and assigns result back
+value ^= 5;        // also bitwise XORs 5 and assigns result back
 
 // |=
 value | 5;         // bitwise ORs 5
 value = value | 5; // bitwise ORs 5 and assigns result back
-value |= value;    // also bitwise ORs 5 and assigns result back
+value |= 5;        // also bitwise ORs 5 and assigns result back
 ```
 
 [p]: /book/types#primitive-types