Add support for horizontal scroll wheel. (Bjorn Winckler)
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index c198dc7..47c10ce 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -136,10 +136,14 @@
|i_<Help>| <Help> stop insert mode and display help window
|i_<Insert>| <Insert> toggle Insert/Replace mode
|i_<LeftMouse>| <LeftMouse> cursor at mouse click
-|i_<MouseDown>| <MouseDown> scroll three lines downwards
-|i_<S-MouseDown>| <S-MouseDown> scroll a full page downwards
-|i_<MouseUp>| <MouseUp> scroll three lines upwards
-|i_<S-MouseUp>| <S-MouseUp> scroll a full page upwards
+|i_<ScrollWheelDown>| <ScrollWheelDown> move window three lines down
+|i_<S-ScrollWheelDown>| <S-ScrollWheelDown> move window one page down
+|i_<ScrollWheelUp>| <ScrollWheelUp> move window three lines up
+|i_<S-ScrollWheelUp>| <S-ScrollWheelUp> move window one page up
+|i_<ScrollWheelLeft>| <ScrollWheelLeft> move window six columns left
+|i_<S-ScrollWheelLeft>| <S-ScrollWheelLeft> move window one page left
+|i_<ScrollWheelRight>| <ScrollWheelRight> move window six columns right
+|i_<S-ScrollWheelRight>| <S-ScrollWheelRight> move window one page right
commands in CTRL-X submode *i_CTRL-X_index*
@@ -441,10 +445,14 @@
|<S-Up>| <S-Up> 1 same as CTRL-B
|<Undo>| <Undo> 2 same as "u"
|<Up>| <Up> 1 same as "k"
-|<MouseDown>| <MouseDown> scroll three lines downwards
-|<S-MouseDown>| <S-MouseDown> scroll a full page downwards
-|<MouseUp>| <MouseUp> scroll three lines upwards
-|<S-MouseUp>| <S-MouseUp> scroll a full page upwards
+|<ScrollWheelDown>| <ScrollWheelDown> move window three lines down
+|<S-ScrollWheelDown>| <S-ScrollWheelDown> move window one page down
+|<ScrollWheelUp>| <ScrollWheelUp> move window three lines up
+|<S-ScrollWheelUp>| <S-ScrollWheelUp> move window one page up
+|<ScrollWheelLeft>| <ScrollWheelLeft> move window six columns left
+|<S-ScrollWheelLeft>| <S-ScrollWheelLeft> move window one page left
+|<ScrollWheelRight>| <ScrollWheelRight> move window six columns right
+|<S-ScrollWheelRight>| <S-ScrollWheelRight> move window one page right
==============================================================================
2.1 Text objects *objects*