New markdown prettifier

* eldoc-box.el (eldoc-box-buffer-hook): Add new prettifier.
(eldoc-box--remove-noise-chars): Remove carriage returns.

eldoc-box.el

@@ -177,6 +177,7 @@ It will be passes with two arguments: WIDTH and HEIGHT of the childframe.")
 (defvar eldoc-box-buffer-hook '(eldoc-box--prettify-markdown-separator
                                 eldoc-box--replace-en-space
                                 eldoc-box--remove-linked-images
+                                eldoc-box--remove-noise-chars
                                 eldoc-box--fontify-html
                                 eldoc-box--condense-large-newline-gaps)
   "Hook run after buffer for doc is setup.
@@ -705,6 +706,13 @@ height."
             nil t)
       (replace-match ""))))
 
+(defun eldoc-box--remove-noise-chars ()
+  "Remove some noise characters like carriage return."
+  (save-excursion
+    (goto-char (point-min))
+    (while (search-forward "\r" nil t)
+      (replace-match ""))))
+
 (defun eldoc-box--fontify-html ()
   "Fontify HTML tags and special entities."
   (save-excursion