Test and improve "Anything"

src/spectator/anything.cr

@@ -1,15 +1,36 @@
 module Spectator
+  # Type dedicated to matching everything.
+  # This is intended to be used as a value to compare against when the value doesn't matter.
+  # Can be used like so:
+  # ```
+  # anything = Spectator::Anything.new
+  # array = ["foo", anything]
+  # expect(["foo", "bar"]).to eq(array)
+  # ```
   struct Anything
+    # Always returns true.
     def ==(other)
       true
     end
 
+    # Always returns true.
     def ===(other)
       true
     end
 
+    # Always returns true.
     def =~(other)
       true
     end
+
+    # Displays "anything".
+    def to_s(io)
+      io << "anything"
+    end
+
+    # Displays "<anything>".
+    def inspect(io)
+      io << "<anything>"
+    end
   end
 end