Update README.md

Added links to the Hacking and Localization guides.
DESIGN: `-i` info
Added `-M` to zsh completions - #247

- May be incomplete. `-M` won't autosuggest package names.
Merge pull request #248 from aspidites/patch-1

Update README.md
Update README.md

Used the repository versions for guide links as those should be (in theory) more accurate and less volatile than the wiki.
Update README.md

Made target for "simple Haskell reference" more specific.
Merge pull request #250 from aspidites/patch-2

Update README.md