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.

java/Main.java

@@ -0,0 +1,6 @@
+public class Main {
+  public static void main(String[] args) {
+    System.out.println(System.getProperty("java.class.path"));
+    System.out.println(Another.whatis());
+  }
+}