fix(reference/stream): HTTP headers are U+0D U+0A (CR LF) separated

correction of the formally wrong comment and place in the example code.

streamlining the example code style on separating multiple headers over multiple lines.

compare Section 4.1 of RFC-2616 etc.

        generic-message = start-line
                          *(message-header CRLF)
                          CRLF
                          [ message-body ]

RFC-2616: https://www.rfc-editor.org/rfc/rfc2616#section-4.1
ok: /reference/stream/functions/stream-context-set-default.xml etc.

reference/stream/functions/stream-context-create.xml

@@ -88,8 +88,9 @@
 $opts = [
   'http' => [
     'method' => "GET",
-    // Use newline \n to separate multiple headers
-    'header' => "Accept-language: en\nCookie: foo=bar",
+    // Use CRLF \r\n to separate multiple headers
+    'header' => "Accept-language: en\r\n" .
+                "Cookie: foo=bar",
   ]
 ];