Merge pull request #131 from AllenSH12/cli_docs

Expand on CLI docs
readme tweaks
Allow both grouped and non-grouped arguments

Fixes #132.
Make sure options gets applied when used without `new`
Write files atomically

Fixes #127.
Merge pull request #133 from kevva/non-grouped

Allow both grouped and non-grouped arguments
improve readability of eb4ba4cde8c1271269f0b81a7ece19275d2b0fbd
1.0.1