[Suggestion]: Improvements to firewalls page

### Page URL

https://documentation.ubuntu.com/server/how-to/security/firewalls/

### Select an option

- [ ] I found what I was looking for
- [ ] I couldn't find what I was looking for
- [x] I found the information, but it was incorrect
- [x] I found the information, but it was incomplete
- [x] I found the information, but it was confusing
- [ ] I encountered a technical issue (e.g., broken link, image not loading)

### Issue Description

To discuss:

- Should reference `nftables` instead of `iptables` (`iptables` is a symlink to `iptables-nft` by default).
- Add a note to allow SSH access before starting `ufw` when activating it remotely.
- Rewrite IP masquerading section to use `nftables`. Probably reference https://wiki.nftables.org/wiki-nftables/index.php/Performing_Network_Address_Translation_(NAT)#Masquerading
- Mention default `ufw` logging in `/var/log/ufw.log` due to rsyslog
- "Check the status" should be right after "Enable or disable ufw" imo.

Start with the firewalls page at documentation.ubuntu.com/server/how-to/security/firewalls/ and review the existing UFW, iptables, IP masquerading, logging, and command-order sections. Done means the page reflects nftables where requested, warns remote users to allow SSH before enabling UFW, documents /var/log/ufw.log, and places status checking after enable/disable instructions.

Written by the indexing model from the issue text.