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.

universe/data_structures_and_algorithms/shuffle.py

@@ -1,34 +0,0 @@
-import random
-
-
-def get_random(floor, ceiling):
-    return random.randrange(floor, ceiling + 1)
-
-
-# shuffle_in_place :: [a] -> IO ()
-def shuffle_in_place(xs):
-    """Fisher-Yates algorithm. Notice that shuffling here is the same as
-    selecting a random permutation of the input set, `xs`."""
-    n = len(xs) - 1
-    for i in range(len(xs)):
-        r = get_random(i, n)
-        xs[i], xs[r] = xs[r], xs[i]
-    return xs
-
-
-# shuffle :: [a] -> [a]
-def shuffle_not_in_place(xs):
-    result = []
-
-    while xs:
-        i = get_random(0, len(xs) - 1)
-        x = xs.pop(i)
-        result.append(x)
-
-    return result
-
-
-xs = [x for x in range(9)]
-print(xs)
-# print(shuffle_not_in_place(xs))
-print(shuffle_in_place(xs[:]))