The file format for each option now features a "Example:" header that
can provide one or more examples that get rendered appropriately in the
output. All options MUST have at least one example or gen.pl complains
at build-time.
This fix also does a few other minor format and consistency cleanups.
Closes#7654
Adds CURLOPT_TLS13_CIPHERS and CURLOPT_PROXY_TLS13_CIPHERS.
curl: added --tls13-ciphers and --proxy-tls13-ciphers
Fixes#2435
Reported-by: zzq1015 on github
Closes#2607
