(response-emit body #:status 200 #:headers '() #:mtime (current-time))
body is the response body, it can be a bytevector or literal string (in HTML).
#:status is the HTTP status, 200 in default, which means OK.
#:headers lets you specify custom HTTP headers. The headers must follow a certain format. Please read Response Headers for details.
#:mtime specifies the modified time in the response. GNU Artanis will generate it for you when not defined.
(emit-response-with-file filename [headers <- '()])
filename is the filename to be sent as a response.
[headers] is the custom HTTP headers.