Add a transcript to test empty match

It currently fails.

unison-src/transcripts/fix4731.md

@@ -0,0 +1,33 @@
+```unison
+structural type Void =
+```
+
+```ucm
+scratch/main> add
+```
+
+We should be able to `match` on empty types like `Void`.
+
+```unison
+Void.absurdly : '{e} Void ->{e} a
+Void.absurdly v = match !v with
+```
+
+```unison
+Void.absurdly : Void -> a
+Void.absurdly v = match v with
+```
+
+And empty `cases` should also work.
+
+```unison
+Void.absurdly : Void -> a
+Void.absurdly = cases
+```
+
+But empty function bodies are not allowed.
+
+```unison:error
+Void.absurd : Void -> a
+Void.absurd x =
+```

unison-src/transcripts/fix4731.output.md

@@ -0,0 +1,61 @@
+``` unison
+structural type Void =
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+  I found and typechecked these definitions in scratch.u. If you
+  do an `add` or `update`, here's how your codebase would
+  change:
+  
+    ⍟ These new definitions are ok to `add`:
+    
+      structural type Void
+
+```
+``` ucm
+scratch/main> add
+
+  ⍟ I've added these definitions:
+  
+    structural type Void
+
+```
+We should be able to `match` on empty types like `Void`.
+
+``` unison
+Void.absurdly : '{e} Void ->{e} a
+Void.absurdly v = match !v with
+```
+
+``` ucm
+
+  Loading changes detected in scratch.u.
+
+    😶
+    
+    I expected some patterns after a match / with or cases but I
+    didn't find any.
+    
+        2 | Void.absurdly v = match !v with
+    
+
+```
+
+
+
+🛑
+
+The transcript failed due to an error in the stanza above. The error is:
+
+
+    😶
+
+    I expected some patterns after a match / with or cases but I
+    didn't find any.
+
+        2 | Void.absurdly v = match !v with
+
+