More struct module docs and docstring tweaks.
diff --git a/Modules/_struct.c b/Modules/_struct.c
index 6a2748f..02a8256 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1605,7 +1605,7 @@
\n\
Pack the values v1, v2, ... according to the format string S.format\n\
and write the packed bytes into the writable buffer buf starting at\n\
-offset. Note that the offset is not an optional argument. See\n\
+offset. Note that the offset is a required argument. See\n\
help(struct) for more on format strings.");
static PyObject *
@@ -1800,8 +1800,8 @@
PyDoc_STRVAR(pack_doc,
"pack(fmt, v1, v2, ...) -> bytes\n\
\n\
-Return a bytes object containing values v1, v2, ... packed according to\n\
-the format string fmt. See help(struct) for more on format strings.");
+Return a bytes object containing the values v1, v2, ... packed according\n\
+to the format string fmt. See help(struct) for more on format strings.");
static PyObject *
pack(PyObject *self, PyObject *args)
@@ -1834,7 +1834,7 @@
\n\
Pack the values v1, v2, ... according to the format string fmt and write\n\
the packed bytes into the writable buffer buf starting at offset. Note\n\
-that the offset is not an optional argument. See help(struct) for more\n\
+that the offset is a required argument. See help(struct) for more\n\
on format strings.");
static PyObject *