Altered command order for generating static sites in TW5.com how-to

Because the rendertiddlers command wipes out the output directory so it needs to come first, not last.

This is related to [this issue](https://github.com/Jermolene/TiddlyWiki5/issues/703) we discussed earlier this year, where I believe you corrected the order in the comments on another issue, but not in the code proper.