fix #64: expand docs on requests to httd(daemon=TRUE) in same process (…

…#65)

R/static.R

@@ -188,7 +188,15 @@ watch_dir = function(
 #'   \code{options(servr.daemon = TRUE)}); if this option was not set,
 #'   \code{daemon = TRUE} if a command line argument \code{-d} was passed to R
 #'   (through \command{Rscript}), or the server is running in an interactive R
-#'   session.
+#'   session. Note, however, that even though the server does not block the
+#'   current R session, it is running in the same single-threaded process.
+#'   Therefore, if a request is made from this same session, the client and
+#'   server \emph{will} block each other. If this is your use case, a better
+#'   solution is to use a package such as \code{callr} to run a \code{servr}
+#'   in a separate process, e.g, \code{rx <- callr::r_bg(function()
+#'   servr::httd(daemon = FALSE)); do_stuff(); rx$kill()} (the
+#'   \code{do_stuff()} function may want to wait a couple of seconds before
+#'   making requests, to allow the server time to start).
 #' @param interval The time interval used to check if an HTML page needs to be
 #'   rebuilt (by default, it is checked every second).
 #' @param baseurl The base URL (the full URL will be