[tech] [spec] TLS statistics

[Stephen]

> * 66 certs are signed by Let's Encrypt
> * 35 pass OpenSSL validation
> * 359 fail OpenSSL validation (not signed by a trusted CA, expired, etc)

66 is more Let's Encrypt certs than I would have guessed. For better or 
worse, they seem a bit out of place in gemini. When I was setting up my 
server, I was almost going to use my Let's Encrypt cert, but I'm glad I 
didn't. The Let's Encrypt method is antithetical to the TOFU model of 
certs. Using a trusted CA is irrelevant and regularly updating your 
certs (often a month in advance of expiry) is not good with TOFU.

> *   3 : Not After 9999

I wish I had gone this way. I think with TOFU this is the only sane way 
(essentially same as ssh host keys).

~Stephen