brackets → parentheses and reflow

Refs #2114

doc/Type/Signature.pod6

@@ -730,7 +730,7 @@ connect two scopes anyway.
 X<|destructuring arguments (Signature)>
 =head2 Destructuring Parameters
 
-Parameters can be followed by a sub-signature in brackets, which will
+Parameters can be followed by a sub-signature in parentheses, which will
 destructure the argument given. The destructuring of a list is just its
 elements:
 
@@ -763,6 +763,7 @@ However, this unpacking of objects as their attributes is only the default
 behavior. To make an object get destructured differently, change its
 L<C<Capture>|/routine/Capture> method.
 
+X<|sub-signature>
 =head2 Sub-signatures
 
 To match against a compound parameter use a sub-signature following the argument
@@ -795,7 +796,8 @@ indicate that the routine's L<C<multi> definitions|multi> can have any L<type
 constraints|#Type_Constraints>. See L<proto|/language/functions#proto> for an
 example.
 
-If bound to a variable arguments can be forwarded as a whole using the slip operator C<|>.
+If bound to a variable arguments can be forwarded as a whole using the slip
+operator C<|>.
 
     sub a(Int $i, Str $s) { say $i.^name ~ ' ' ~ $s.^name }
     sub b(|c) { say c.^name; a(|c) }