Splice ./universe directory into ./

Manually merging:
- README.md: I added the description from universe/README.md into the heading of
  dotfiles/README.md.
- .envrc: dotfiles/.envrc was a superset of universe/.envrc
- .gitignore: Adding some of the ignored patterns from universe/.gitignore to
  dotfiles/.gitignore

Everything else here should be a simple rename.

crack_the_coding_interview/to_tree.hs

@@ -0,0 +1,11 @@
+data Tree a = Node a [Tree a] deriving (Show)
+
+withRoot :: [a] -> [Tree a]
+withRoot xs = xs |> toThing |> fmap buildTree
+
+buildTree :: (a, [a])
+
+
+toTree :: [a] -> Tree a
+toTree [x]      = Node x []
+toTree [x | xs] = Node x (toTree xs)