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.

third_party/lisp/prove.nix

@@ -0,0 +1,35 @@
+{
+  depot ? import <depot> {},
+  universe? import <universe> {},
+  ...
+}:
+
+let
+  src = builtins.fetchGit {
+    url = "https://github.com/fukamachi/prove.git";
+    rev = "5d71f02795b89e36f34e8c7d50e69b67ec6ca2de";
+  };
+in depot.nix.buildLisp.library {
+  name = "prove";
+  deps = [
+    depot.third_party.lisp.cl-ppcre
+    depot.third_party.lisp.cl-ansi-text
+    depot.third_party.lisp.alexandria
+    depot.third_party.lisp.uiop
+    universe.third_party.lisp.cl-colors
+  ];
+  srcs = [
+    "${src}/src/asdf.lisp"
+    "${src}/src/suite.lisp"
+    "${src}/src/color.lisp"
+    "${src}/src/output.lisp"
+    "${src}/src/prove.lisp"
+    "${src}/src/report.lisp"
+    "${src}/src/reporter.lisp"
+    "${src}/src/test.lisp"
+    "${src}/src/reporter/dot.lisp"
+    "${src}/src/reporter/fiveam.lisp"
+    "${src}/src/reporter/list.lisp"
+    "${src}/src/reporter/tap.lisp"
+  ];
+}