Pro-tip
Get your own domain and host your own NIP-05
This is mine here:
Hey nostr:nprofile1qydhwumn8ghj7emvv4shxmmwv96x7u3wv3jhvtmjv4kxz7gpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhszxrhwden5te0dehhxerjd9mx2tnpwpcz7un9d3shjqgkwaehxw309aex2mrp0yhx6mmnw3ezuur4vghsz9mhwden5te0wfjkccte9ec8y6tdv9kzumn9wshszxthwden5te0wfjkccte9eekummjwsh8xmmrd9skctcprdmhxue69uhhgetnw3ex2mrp0yhxummnw3erztnrdakj7qgkwaehxw309ahx7um5wghx6ctvd9hzummwdshszfthwden5te0v93xxer9vennyvpjxscrzvp5xgcr2dpsxqh8s7t69amrztmhwvq3vamnwvaz7tm8wfjk2mnnda6kctnnwpskxef0qyghwumn8ghj7mn0wd68ytnvv9hxgtcpr4mhxue69uhhg6p39ehx7um5wghx2ctjde4hyatz9eu8j730qywhwumn8ghj7cn0wd68ytnzd96xxmmfde68smmtduhxxmmd9uq3samnwvaz7tmjv4kxz7tn9ejxjem8dahjucm0d5hsz9mhwden5te0dehhxarj9ekx7un9de685tnfwvhsz9mhwden5te0wfjkccte9ejx2a3wvfj8wtn5duhsz8mhwden5te0vfhhxarj9ekxjemgw3hxjmn8wdcx7un99e3k7mf0qyw8wumn8ghj7en9v4j8xtnwdaehgu3wvfskuep0d4jk6etnqqsqgc0uhmxycvm5gwvn944c7yfxnnxm0nyh8tt62zhrvtd3xkj8fhgcdjpln -- I have a NIP-05 (Svoboda@BitcoinNostr.com) and can no longer respond to anyone. Also noticed that my profile does not have any of my activity since yesterday afternoon. Any ideas?

Pro-tip
Get your own domain and host your own NIP-05
This is mine here:
Can you point me to a resource that shows all the optionality?
I can't, but I can explain the json file.
Copy mine.
Replace the "mike" with your own name.
Replace the string to the right with the hex of your npub.
You can obtain the hex of your npub here:
https://nostrcheck.me/converter/
Also replace the string at the top of the relay list with your hex npub.
Then replace the relays at the bottom with your primary relays.
Be careful not to change commas, quotes, brackets etc....
Upload the "nostr.json" file to your web server, making sure it is in the directory:
/.well-known
at the root of your HTML content
Then your NIP-05 will be: