[vte] docs: Add regex flag requirements

[Christian Persch <chpe src gnome org>]

commit f0162eaf518ee260d08b7a794ff6f493df356433
Author: Christian Persch <chpe src gnome org>
Date:   Sun Mar 29 23:27:57 2020 +0200

    docs: Add regex flag requirements
    
    Fixes: https://gitlab.gnome.org/GNOME/vte/issues/223

 src/vtegtk.cc | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/vtegtk.cc b/src/vtegtk.cc
index 8edb9d9b..8f879512 100644
--- a/src/vtegtk.cc
+++ b/src/vtegtk.cc
@@ -2156,6 +2156,8 @@ vte_terminal_match_add_gregex(VteTerminal *terminal,
  * user moves the mouse cursor over a section of displayed text which matches
  * this expression, the text will be highlighted.
  *
+ * Note that @regex should have been created using the %PCRE2_MULTILINE flag.
+ *
  * Returns: an integer associated with this expression
  *
  * Since: 0.46
@@ -2465,6 +2467,8 @@ vte_terminal_search_find_next (VteTerminal *terminal)
  *
  * Sets the regex to search for. Unsets the search regex when passed %NULL.
  *
+ * Note that @regex should have been created using the %PCRE2_MULTILINE flag.
+ *
  * Since: 0.46
  */
 void