[guides] Add the SlideGuide describing column and row movement (#2529)

Co-authored-by: anjakefala <[email protected]>

Author: thejud

visidata/guides/SlideGuide.md

@@ -0,0 +1,26 @@
+# The Slide Guide
+
+The key bindings are based on the vi movement keys (hjkl).
+
+## How to move columns
+
+- {help.commands.slide_left}
+- {help.commands.slide_right}
+
+- {help.commands.slide_leftmost}
+- {help.commands.slide_rightmost}
+
+- {help.commands.slide_left_n}
+- {help.commands.slide_right_n}
+
+## How to move rows
+
+- {help.commands.slide_down}
+- {help.commands.slide_up}
+
+- {help.commands.slide_bottom}
+- {help.commands.slide_top}
+
+- {help.commands.slide_down_n}
+- {help.commands.slide_up_n}
+