Add vimdiff and sdiff command.

README.md

@@ -207,7 +207,9 @@ Notes:
 
 - If you ever need to write a tab literal in a command line in Bash (e.g. for the -t argument to sort), press **ctrl-v** **[Tab]** or write `$'\t'` (the latter is better as you can copy/paste it).
 
-- The standard tools for patching source code are `diff` and `patch`. See also `diffstat` for summary statistics of a diff. Note `diff -r` works for entire directories. Use `diff -r tree1 tree2 | diffstat` for a summary of changes.
+- The standard tools for patching source code are `diff` and `patch`. See also `diffstat` for summary statistics of a diff and `sdiff` easier to read diff. Note `diff -r` works for entire directories. Use `diff -r tree1 tree2 | diffstat` for a summary of changes.
+
+- Use `vimdiff` to compare and edit files. Really efficient !
 
 - For binary files, use `hd` for simple hex dumps and `bvi` for binary editing.