Add a note about escaping console format tags

Author: julienfalque

console/coloring.rst

@@ -65,6 +65,14 @@ You can also set these colors and options directly inside the tagname::
     // bold text on a yellow background
     $output->writeln('<bg=yellow;options=bold>foo</>');
 
+.. note::
+
+    If you need to render a tag literally, you must escape it with a backslash: ``\<info>``.
+    You can use :method:`OutputFormatter::escape() <Symfony\\Component\\Console\\Formatter\\OutputFormatter::escape>`
+    to escape all tags of a given text.
+
+    If you need to render a literal backslash before a tag, replace it with ``<<``.
+
 .. _Cmder: http://cmder.net/
 .. _ConEmu: https://conemu.github.io/
 .. _ANSICON: https://github.com/adoxa/ansicon/releases