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.

data_structures_and_algorithms/merge-sort.py

@@ -0,0 +1,28 @@
+
+
+
+# merge :: [a] -> [a] -> [a]
+# merge([], []): []
+# merge(xs, []): xs
+# merge([], ys): ys
+# merge(xs@[x|xs'], ys@[y|ys'])
+#   when y =< x: cons(y, merge(xs, ys'))
+#   when x < y:  cons(x, merge(xs', ys))
+def merge(xs, ys):
+    if xs == [] and ys == []:
+        return []
+    elif ys == []:
+        return xs
+    elif xs == []:
+        return ys
+    else:
+        x = xs[0]
+        y = ys[0]
+
+        if y <= x:
+            return [y] + merge(xs, ys[1:])
+        else:
+            return [x] + merge(xs[1:], ys)
+        
+print(merge([3, 4, 6, 10, 11, 15],
+            [1, 5, 8, 12, 14, 19]))