Update spec.txt.

Author: jgm

test/spec.txt

@@ -7338,12 +7338,13 @@ A [link destination](@) consists of either
   closing `>` that contains no line breaks or unescaped
   `<` or `>` characters, or
 
-- a nonempty sequence of characters that does not include
-  ASCII space or control characters, and includes parentheses
-  only if (a) they are backslash-escaped or (b) they are part of
-  a balanced pair of unescaped parentheses.  (Implementations
-  may impose limits on parentheses nesting to avoid performance
-  issues, but at least three levels of nesting should be supported.)
+- a nonempty sequence of characters that does not start with
+  `<`, does not include ASCII space or control characters, and
+  includes parentheses only if (a) they are backslash-escaped or
+  (b) they are part of a balanced pair of unescaped parentheses.
+  (Implementations may impose limits on parentheses nesting to
+  avoid performance issues, but at least three levels of nesting
+  should be supported.)
 
 A [link title](@)  consists of either
 
@@ -7446,7 +7447,7 @@ Pointy brackets that enclose links must be unescaped:
 ```````````````````````````````` example
 [link](<foo\>)
 .
-<p><a href="%3Cfoo%3E">link</a></p>
+<p>[link](&lt;foo&gt;)</p>
 ````````````````````````````````