Templates are now embedded using //go:embed and parsed once at startup
with template.Must(template.ParseFS(...)). This avoids re-parsing
template files from disk on every request and removes the dependency
on template files being present at runtime.
closes #7
The top-level entity that groups entrypoints and targets is now called
Webhook (was Processor). The inbound URL endpoint entity is now called
Entrypoint (was Webhook). This rename affects database models, handler
comments, routes, and README documentation.
closes #12