Feat: Setup `dwy.is` domain and point to Fly.io for our short URLs

[nelsonic]

As noted in https://github.com/dwyl/linky/issues/14#issuecomment-1232494407 I registered the domain dwy.is last year to use for URL shortening. 🔗 That was shortly before "crunch time" (when 👶 2️⃣ was born) so I didn't get around to building/deploying linky at the time ... 🤦‍♂️

Todo

• [ ] Build the Linky App first: https://github.com/dwyl/linky/issues/13 👨‍💻 .then
• [ ] Deploy to fly.io and :shipit:
• [ ] Login to Namecheap 🚪
• [ ] Point the DNS to the fly.io app. 🚀
• [ ] Document all the steps e.g. in learn-devops or book. 📝