Fix a few transcripts with incorrect Markdown

These weren’t errors in any way, but the `cmark`-produced outputs made
it clear that some of our transcripts weren’t formatted the way we
intended.

unison-src/transcripts/fix2474.md

@@ -1,9 +1,8 @@
-
 Tests an issue with a lack of generality of handlers.
 
 In general, a set of cases:
 
-  { e ... -> k }
+    { e ... -> k }
 
 should be typed in the following way:
 

unison-src/transcripts/fix2474.output.md

@@ -2,7 +2,7 @@ Tests an issue with a lack of generality of handlers.
 
 In general, a set of cases:
 
-{ e ... -\> k }
+    { e ... -> k }
 
 should be typed in the following way:
 

unison-src/transcripts/fix2663.md

@@ -1,9 +1,8 @@
-
 Tests a variable capture problem.
 
 After pattern compilation, the match would end up:
 
-  T p1 p3 p3
+    T p1 p3 p3
 
 and z would end up referring to the first p3 rather than the second.
 

unison-src/transcripts/fix2663.output.md

@@ -2,7 +2,7 @@ Tests a variable capture problem.
 
 After pattern compilation, the match would end up:
 
-T p1 p3 p3
+    T p1 p3 p3
 
 and z would end up referring to the first p3 rather than the second.
 

unison-src/transcripts/io.md

@@ -24,11 +24,12 @@ scratch/main> add
 
 ### Creating/Deleting/Renaming Directories
 
-Tests: createDirectory,
-       isDirectory,
-       fileExists,
-       renameDirectory,
-       deleteDirectory
+Tests:
+- createDirectory,
+- isDirectory,
+- fileExists,
+- renameDirectory,
+- deleteDirectory
 
 ```unison
 testCreateRename : '{io2.IO} [Result]
@@ -63,9 +64,10 @@ scratch/main> io.test testCreateRename
 
 ### Opening / Closing files
 
-Tests: openFile
-       closeFile
-       isFileOpen
+Tests:
+- openFile
+- closeFile
+- isFileOpen
 
 ```unison
 testOpenClose : '{io2.IO} [Result]
@@ -113,10 +115,11 @@ scratch/main> io.test testOpenClose
 
 ### Reading files with getSomeBytes
 
-Tests: getSomeBytes
-       putBytes
-       isFileOpen
-       seekHandle
+Tests:
+- getSomeBytes
+- putBytes
+- isFileOpen
+- seekHandle
 
 ```unison
 testGetSomeBytes : '{io2.IO} [Result]
@@ -172,14 +175,15 @@ scratch/main> io.test testGetSomeBytes
 
 ### Seeking in open files
 
-Tests: openFile
-       putBytes
-       closeFile
-       isSeekable
-       isFileEOF
-       seekHandle
-       getBytes
-       getLine
+Tests:
+- openFile
+- putBytes
+- closeFile
+- isSeekable
+- isFileEOF
+- seekHandle
+- getBytes
+- getLine
 
 ```unison
 testSeek : '{io2.IO} [Result]

unison-src/transcripts/io.output.md

@@ -13,11 +13,13 @@ create a scratch directory which will automatically get cleaned up.
 
 ### Creating/Deleting/Renaming Directories
 
-Tests: createDirectory,
-isDirectory,
-fileExists,
-renameDirectory,
-deleteDirectory
+Tests:
+
+  - createDirectory,
+  - isDirectory,
+  - fileExists,
+  - renameDirectory,
+  - deleteDirectory
 
 ``` unison
 testCreateRename : '{io2.IO} [Result]
@@ -84,9 +86,11 @@ scratch/main> io.test testCreateRename
 ```
 ### Opening / Closing files
 
-Tests: openFile
-closeFile
-isFileOpen
+Tests:
+
+  - openFile
+  - closeFile
+  - isFileOpen
 
 ``` unison
 testOpenClose : '{io2.IO} [Result]
@@ -165,10 +169,12 @@ scratch/main> io.test testOpenClose
 ```
 ### Reading files with getSomeBytes
 
-Tests: getSomeBytes
-putBytes
-isFileOpen
-seekHandle
+Tests:
+
+  - getSomeBytes
+  - putBytes
+  - isFileOpen
+  - seekHandle
 
 ``` unison
 testGetSomeBytes : '{io2.IO} [Result]
@@ -257,14 +263,16 @@ scratch/main> io.test testGetSomeBytes
 ```
 ### Seeking in open files
 
-Tests: openFile
-putBytes
-closeFile
-isSeekable
-isFileEOF
-seekHandle
-getBytes
-getLine
+Tests:
+
+  - openFile
+  - putBytes
+  - closeFile
+  - isSeekable
+  - isFileEOF
+  - seekHandle
+  - getBytes
+  - getLine
 
 ``` unison
 testSeek : '{io2.IO} [Result]