Describe 'surrogateescape' in the documentation.
Also, improve some docstring descriptions of the 'errors' parameter.
Closes #14015.
diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
index b5cd176..4a7e758 100644
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -168,8 +168,8 @@
"'strict' to raise a ValueError exception if there is an encoding error\n"
"(the default of None has the same effect), or pass 'ignore' to ignore\n"
"errors. (Note that ignoring encoding errors can lead to data loss.)\n"
-"See the documentation for codecs.register for a list of the permitted\n"
-"encoding error strings.\n"
+"See the documentation for codecs.register or run 'help(codecs.Codec)'\n"
+"for a list of the permitted encoding error strings.\n"
"\n"
"newline controls how universal newlines works (it only applies to text\n"
"mode). It can be None, '', '\\n', '\\r', and '\\r\\n'. It works as\n"