Convert Doc v1 transcripts to v2

This does a very superficial conversion – it doesn’t correct all of the
verbiage that describes how to do things in v1, just changes the actual
syntax.

unison-src/transcripts/doc-formatting.md

@@ -3,13 +3,13 @@ This transcript explains a few minor details about doc parsing and pretty-printi
 Docs can be used as inline code comments.
 
 ```ucm:hide
-scratch/main> builtins.merge
+scratch/main> builtins.mergeio
 ```
 
 ```unison
 foo : Nat -> Nat
 foo n =
-  _ = [: do the thing :]
+  _ = {{ do the thing }}
   n + 1
 ```
 
@@ -20,10 +20,10 @@ scratch/main> add
 scratch/main> view foo
 ```
 
-Note that `@` and `:]` must be escaped within docs.
+Note that `{{`, `@`, and `}}` must be escaped within docs.
 
 ```unison
-escaping = [: Docs look [: like \@this \:] :]
+escaping = {{ Docs look --doc open-- like --amphora--this --doc close-- }}
 ```
 
 ```ucm:hide
@@ -33,16 +33,16 @@ scratch/main> add
 scratch/main> view escaping
 ```
 
-(Alas you can't have `\@` or `\:]` in your doc, as there's currently no way to 'unescape' them.)
+(Alas you can't have `\@` or `\}}` in your doc, as there's currently no way to 'unescape' them.)
 
 ```unison
 -- Note that -- comments are preserved within doc literals.
-commented = [:
+commented = {{
   example:
 
     -- a comment
     f x = x + 1
-:]
+}}
 ```
 
 ```ucm:hide
@@ -60,7 +60,7 @@ Handling of indenting in docs between the parser and pretty-printer is a bit fid
 -- The leading and trailing spaces are stripped from the stored Doc by the
 -- lexer, and one leading and trailing space is inserted again on view/edit
 -- by the pretty-printer.
-doc1 = [:   hi   :]
+doc1 = {{   hi   }}
 ```
 
 ```ucm:hide
@@ -71,15 +71,15 @@ scratch/main> view doc1
 ```
 
 ```unison
--- Lines (apart from the first line, i.e. the bit between the [: and the
+-- Lines (apart from the first line, i.e. the bit between the {{ and the
 -- first newline) are unindented until at least one of
 -- them hits the left margin (by a post-processing step in the parser).
 -- You may not notice this because the pretty-printer indents them again on
 -- view/edit.
-doc2 = [: hello
+doc2 = {{ hello
             - foo
             - bar
-          and the rest. :]
+          and the rest. }}
 ```
 
 ```ucm:hide
@@ -90,7 +90,7 @@ scratch/main> view doc2
 ```
 
 ```unison
-doc3 = [: When Unison identifies a paragraph, it removes any newlines from it before storing it, and then reflows the paragraph text to fit the display window on display/view/edit.
+doc3 = {{ When Unison identifies a paragraph, it removes any newlines from it before storing it, and then reflows the paragraph text to fit the display window on display/view/edit.
 
 For these purposes, a paragraph is any sequence of non-empty lines that have zero indent (after the unindenting mentioned above.)
 
@@ -101,7 +101,7 @@ For these purposes, a paragraph is any sequence of non-empty lines that have zer
    is not treated | either.
 
 Note that because of the special treatment of the first line mentioned above, where its leading space is removed, it is always treated as a paragraph.
-   :]
+   }}
 ```
 
 ```ucm:hide
@@ -112,11 +112,11 @@ scratch/main> view doc3
 ```
 
 ```unison
-doc4 = [: Here's another example of some paragraphs.
+doc4 = {{ Here's another example of some paragraphs.
 
           All these lines have zero indent.
 
-            - Apart from this one. :]
+            - Apart from this one. }}
 ```
 
 ```ucm:hide
@@ -130,10 +130,10 @@ scratch/main> view doc4
 -- The special treatment of the first line does mean that the following
 -- is pretty-printed not so prettily.  To fix that we'd need to get the
 -- lexer to help out with interpreting doc literal indentation (because
--- it knows what columns the `[:` was in.)
-doc5 = [:   - foo
+-- it knows what columns the `{{` was in.)
+doc5 = {{   - foo
             - bar
-          and the rest. :]
+          and the rest. }}
 ```
 
 ```ucm:hide
@@ -145,11 +145,11 @@ scratch/main> view doc5
 
 ```unison
 -- You can do the following to avoid that problem.
-doc6 = [:
+doc6 = {{
             - foo
             - bar
           and the rest.
-       :]
+       }}
 ```
 
 ```ucm:hide
@@ -163,7 +163,7 @@ scratch/main> view doc6
 
 ```unison
 -- Check empty doc works.
-empty = [::]
+empty = {{}}
 
 expr = foo 1
 ```
@@ -175,7 +175,7 @@ scratch/main> view empty
 ```
 
 ```unison
-test1 = [:
+test1 = {{
 The internal logic starts to get hairy when you use the \@ features, for example referencing a name like @List.take.  Internally, the text between each such usage is its own blob (blob ends here --> @List.take), so paragraph reflow has to be aware of multiple blobs to do paragraph reflow (or, more accurately, to do the normalization step where newlines with a paragraph are removed.)
 
 Para to reflow: lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor ending in ref @List.take
@@ -211,7 +211,7 @@ para line lorem ipsum dolor lorem ipsum dolor lorem ipsum dolor lorem ipsum dolo
 -- note the leading space below
   @[signature] List.take
 
-:]
+}}
 ```
 ```ucm:hide
 scratch/main> add
@@ -222,8 +222,8 @@ scratch/main> view test1
 
 ```unison
 -- Regression test for #1363 - preservation of spaces after @ directives in first line when unindenting
-reg1363 = [: `@List.take foo` bar
-  baz :]
+reg1363 = {{ `@List.take foo` bar
+  baz }}
 ```
 ```ucm:hide
 scratch/main> add
@@ -236,10 +236,10 @@ scratch/main> view reg1363
 -- Demonstrate doc display when whitespace follows a @[source] or @[evaluate]
 -- whose output spans multiple lines.
 
-test2 = [:
+test2 = {{
   Take a look at this:
   @[source] foo    ▶    bar
-:]
+}}
 ```
 ```ucm:hide
 scratch/main> add