src: fix the misalinged text on "node --help"

The alignment of the argument descriptions in the "node --help"
text is off. This commit fixes the issue by adding two spaces
before each of the argument description.

PR-URL: https://github.com/nodejs/node/pull/10948
Fixes: https://github.com/nodejs/node/issues/10935


Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Josh Gavant <josh.gavant@outlook.com>