Simplest solution:
Have a line in your conf\entities.local.conf file that looks like this:
\t   
(nb, this is the version I have in mine, and it creates two tab characters).
However, as others have noted, for pre-formatted programming code blocks, a monospace font with spaces are generally preferred. For general text layout, it's better to either use a table to layout the text, or to use css to create an indent.