Hi,
I know this is not about the language itself, rather about the people being able to reach its definition and resources, so please bear with me.
Using those sites without https is at least discouraged (prominent "not secure" warnings), when not even blocked by browsers nowadays.
This makes the browsers refuse to connect to it, throwing errors like
net::ERR_CERT_COMMON_NAME_INVALID
I suggest creating a certificate for the domain
picat-lang.org and using it.
Letsencrypt offers free certificates (that need to be renewed every 3 months, it can be automatised), so there should be no costs incurred.
best regards,
Cristian