amendet README.md

README.md

@@ -6,10 +6,10 @@ A small text editor written in Python running on PYBoard, allowing to edit files
 
 - Use USB_VCP or UART for input and output.
 - Changed the read keyboard function to comply with slow byte-by-byte input on serial lines.
-- Added support for TAB, BACKTAB, SAVE, FIND, REPLACE, GOTO line, YANK (delete line into a buffer), DUP (copy line into a buffer), ZAP (insert buffer)
-- Join Lines by 'Delete Char' at the end or Backspace at the beginning of a line, Auto-indent for ENTER, context sensitive TAB, BACKTAB and HOME
+- Added support for TAB, BACKTAB, SAVE, FIND, REPLACE, GOTO line, YANK (delete line into a buffer), DUP (copy line into a buffer), ZAP (insert buffer) and UNDO
+- Join Lines by 'Delete Char' at the end or Backspace at the beginning of a line, Auto-indent for ENTER, context sensitive TAB, BACKTAB, HOME and and BACKSPACE
 - Moved main into a function with some optional parameters
-- Added an optional status line and single line prompts for QUIT, SAVE, FIND, REPLACE, GOTO, and Toggles. 
+- Added an optional status line and single line prompts for QUIT, SAVE, FIND, REPLACE, GOTO, and Toggles.
   The status line can be turned (almost) off for slow connections.
 - Support of the basic mouse functions scrolling up/down and setting the cursor.
 
@@ -24,8 +24,8 @@ The editor works also well in a Linux or MAC terminal environment, with both pyt
 - README.md: This one
 - pe.py: Editor Python file with all functions in a stripped down version for PyBoard only without comments
 - pemin.py: Editor Python file with a reduced function set in a stripped down version for PyBoard only without comments
-- tuning_pye.py: A file with some improved replacements for functions of pye: 
-a) find_in_file() supporting regular expressions, 
+- tuning_pye.py: A file with some improved replacements for functions of pye:
+a) find_in_file() supporting regular expressions,
 b) line_edit() supporting cursor keys, and
 c) expandtabs() with a second argument for tabsize (not for pye, but maybe useful)
 - strip.sh: sample Shell script which creates the different variants out of pye.py using cpp