Avoid double negatives

[l0b0]

For example:

You shouldn’t use a pager if stdin or stdout is not an interactive terminal.

Could be written as:

Use a pager only if stdout is an interactive terminal.

(Also, why is stdin mentioned here? If I run grep foo < bar, stdin is not an interactive terminal, but I still would want a pager for grep's stdout.)

[bfirsh]

Thanks for the suggestion! Pull requests welcome. :)