patch 9.1.0836: The vimtutor can be improved

Problem:  the vimtutor can be improved
Solution: port and include the interactive vimtutor plugin from Neovim
          (by Felipe Morales) (Yegappan Lakshmanan)

closes: #6414

Signed-off-by: Christian Brabandt <cb@256bit.org>
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
diff --git a/runtime/doc/Make_all.mak b/runtime/doc/Make_all.mak
index f36ad7e..ccc429b 100644
--- a/runtime/doc/Make_all.mak
+++ b/runtime/doc/Make_all.mak
@@ -75,6 +75,7 @@
 	pi_paren.txt \
 	pi_spec.txt \
 	pi_tar.txt \
+	pi_tutor.txt \
 	pi_vimball.txt \
 	pi_zip.txt \
 	popup.txt \
@@ -228,6 +229,7 @@
 	pi_paren.html \
 	pi_spec.html \
 	pi_tar.html \
+	pi_tutor.html \
 	pi_vimball.html \
 	pi_zip.html \
 	popup.html \