Lesson 9: Damaging the Robot Goals are confusing

The Goals description is confusing:

```
In our game, the main character has a certain amount of health. When it gets hit, the health should go down by a varying amount of damage.

Add to the take_damage() function so it subtracts the amount to the predefined health variable.

The robot starts with 100 health and will take 50 damage.
```

Especially the second paragraph: `Add to the take_damage() [...]`.

It's also unclear that `amount`, the `take_damage()` function parameter will have the value `50`. It can be interpreted that the student has to subtract a constant `50` value.

Open based on: https://gdquest.mavenseed.com/community/15797-damaging-the-robot