Add risitas command

```python
# Query web
async with aiohttp.ClientSession() as session:
    async with session.get("http://aws.random.cat/meow") as r:
        if r.status == 200:
            js = await r.json()

# Render pictures
embed = disnake.Embed()
embed.set_image(file=disnake.File("path/to/file.png"))
await channel.send(embed=embed)
```

https://risibank.fr/api/v1/docs