message: readme: Mention the relative submodules path / fork issue.
diff: @@ -43,6 +43,8 @@ git clone https://github.com/infinit/elle --recursive # Clone elle and its submo
  > *Note:* If you cloned it using the GitHub "clone" button, do not forget to run `git submodule update --init --recursive`!
  +> *Note:* If you *forked* Elle, you'll also need to fork the following repositories too: `drake`, `dokan`, `libutp`, `miniupnp`. The reason why is detailed on following GitHub issue: `https://github.com/infinit/elle/issues/6`.
  +
  ## Structure
  As mentioned earlier, Elle is composed of a set of sub-libraries, designed to ease C++ development through robust and flexible implementations, including:
  