PEG: Fix bug#76555

* doc/lispref/peg.texi (Parsing Expression Grammars):
Fix `define-peg-ruleset` example.

* lisp/progmodes/peg.el (define-peg-rule): Fix indent rule.

doc/lispref/peg.texi

@@ -141,8 +141,8 @@ Define @var{name} as an identifier for @var{rules}.
 @example
 @group
 (define-peg-ruleset number-grammar
+        ;; `digit' here references the definition above.
         '((number sign digit (* digit))
-          digit  ;; A reference to the definition above.
           (sign (or "+" "-" ""))))
 @end group
 @end example

lisp/progmodes/peg.el

@@ -369,7 +369,7 @@ defaults to `ignore'."
   "Define PEG rule NAME as equivalent to PEXS.
 The PEG expressions in PEXS are implicitly combined with the
 sequencing `and' operator of PEG grammars."
-  (declare (indent 1))
+  (declare (indent 2))
   (let ((inline nil))
     (while (keywordp (car pexs))
       (pcase (pop pexs)