minor typo in the "index" manuel

<img width="1797" height="60" alt="Image" src="https://github.com/user-attachments/assets/6eceeb35-25e4-411a-8caf-7da6355dde46" />

```
print "SNES address $018000 in the current mapping mode is equivalent to PC address 0x",dec(snestopc($018000))
```
I'm pretty sure you meant to use `hex(snestopc($018000))`, not `dec(snestopc($018000))`