Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - Add tutorial for reclass-doc tool in documentation

    JIRA: FUEL-293

    Change-Id: I2612e8d63875dca4d05f8c30db24a5ae84cc8dea
    Signed-off-by: Charalampos Kominos <Charalampos.Kominos@enea.com>
    Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 94954c13104b7f7e3bd04a7b5fdbae84a93457ac)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 7020f4a..befec9a 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 7020f4a880f0b7a5d8941da4001061dcc9c56793
+Subproject commit befec9ab2c6fb526afa105f1ce7d71a58a5facac