rst files get saved with tabs replacing spaces

[jaraco]

It seems like this change causes problems with .rst files, which were using spaces for indentation. Now when I try to save a README in an editor that supports editorconfig, the spaces get replaced by tabs.

Originally posted by @jaraco in #43 (comment)

[jaraco]

I do actually prefer tabs to spaces. Maybe I should try applying the tabs.

[jaraco]

According to this link, spaces are preferred but tabs are allowed, and tabs are treated like 8 spaces. I think things look better with spaces, and since they're recommended, it's probably better to stick with them. Unlike with code, tabstops are less visually helpful in rst.