ESC: enter the 'VIEW' mode
     e: enter the 'EDIT' mode
     q: quit from the text editor
     w: write file to disk
     a: cat current line to previous one
     d: cut current line to copy buffer
     c: copy current line to copy buffer
     p: paste line from copy buffer
     s: push text buffer to undo buffer
     l: pull text buffer from undo buffer
     h: toggle syntax highlighting
     x: execute GNUsed command
   0-9: navigate throughout the file
Arrows: move cursor
PgDown: scroll 1/4 of the screen downwards
  PgUp: scroll 1/4 of the screen upwards
  HOME: move cursor to the begining of the current line
   END: move cursor to the end of the current line

Search:

/hello/=              # puts cursor on the line where first occurrence of "hello" is found
10,20 {/hello/=}      # same as above but within lines 10-20
10,$ {/hello/=}       # same as above but from line 10 to the end of document


Replace:

s/hello/hi/g          # replace "hello" with "hi" in the entire document
10 s/hello/hi/        # same but only on line 10
10,20 s/^/    /       # set indentation 4 spaces within the lines 10-20
s/ *$//g              # remove trailing spaces entire document

Move:

1,10d                 # delete lines 1-10
1,10H; 11g            # copy lines 1-10 and paste to line 11
1,10H; 11g 1,10d      # cut lines 1-10 and paste to line 11

NOTE: to use GNUsed on Windows you need first to install it and make
      sure 'sed.exe' utility is available system wide, you can find
      the windows installer file in this repo in a folder 'sed'.

$ ego                 # opens editor with 'out.txt' source file name
$ ego my_file.txt     # opens editor with 'my_file.txt' if it exists,
                      # otherwise sets source filename to 'my_file.txt'