emacs docs: rstdoc.el: consistent single quote conversions

With text-quoting-style 'grave keeps "'" and "`" quotes unaltered
for further processing done by this code (regardless of locale...).
The tools that read the reStructuredText markup generated can do
their styling instead.

Added temporary conversions of ' and ` to \001 and \002 so that
's and `s outside of `...' and `...` are converted separately
('s restored back to ' and `s converted to \`).

Both `...' and `...` are finally "converted" to `...` (not ``...``).
https://docutils.sourceforge.io/docs/user/rst/quickref.html documents
that as `interpreted text`:

 "The rendering and meaning of interpreted text is domain- or
  application-dependent. It can be used for things like index
  entries or explicit descriptive markup (like program identifiers)."

Which looks pretty much right.

emacs/rstdoc.el

@@ -40,6 +40,7 @@
   "Write docstrings from IN-FILE to OUT-FILE."
   (load-file in-file)
   (let* ((definitions (cdr (assoc (expand-file-name in-file) load-history)))
+	 (text-quoting-style 'grave)
 	 (doc-hash (make-hash-table :test 'eq)))
     (mapc
      (lambda (elt)
@@ -65,11 +66,14 @@
   (insert "\n"))
 
 (defvar rst--escape-alist
-  '(("\\\\='" . "\\\\'")
+  '( ("\\\\='" . "\001")
-    ("\\([^\\]\\)'" . "\\1`")
+     ("`\\([^\n`']*\\)[`']" . "\002\\1\002") ;; good enough for now...
-    ("^[[:space:]\t]*$" . "|br|")
+     ("`" . "\\\\`")
-    ("^[[:space:]\t]" . "|indent| "))
+     ("\001" . "'")
-  "List of (regex . replacement) pairs.")
+     ("\002" . "`")
+     ("^[[:space:]]*$" . "|br|")
+     ("^[[:space:]]" . "|indent| "))
+    "list of (regex . replacement) pairs")
 
 (defun rstdoc--rst-quote-string (str)
   (with-temp-buffer