Various errors on the openbsd instructions

https://certbot.eff.org/instructions?ws=nginx&os=opbsd6

I'm reporting a slight mistake. On the instructions for installing certbot on openbsd, it gives a few commands that use `sudo` instead of `doas`.
For example:
```
sudo certbot certonly --standalone
sudo certbot certonly --webroot
echo "0 0,12 * * * root python -c 'import random; import time; time.sleep(random.random() * 3600)' && sudo certbot renew -q" | sudo tee -a /etc/crontab > /dev/null
```

I should also mention that the instructions for adding a wildcard domain are unclear.
For example the command `pkg_add -cloudflare` just gives me `pkg_add: bad list oudflare: No such file or directory`. I'm don't think packages like this exist on openbsd.

Thank you for your time and attention to this matter.