replacing IO common feature list with a .. content:: directive
diff --git a/user_guide.rst b/user_guide.rst
index f83bd20..26e7f41 100644
--- a/user_guide.rst
+++ b/user_guide.rst
@@ -239,15 +239,8 @@
The :cell:`sky130_fd_io__gpio` and :cell:`sky130_fd_io__sio` buffers contain the following common features:
-1. Eight drive strength modes
-2. Independent control of input and output buffer enables
-3. Input buffer threshold select
-4. I/O supply and Internal supply level input buffer outputs
-5. Selectable output edge rate control
-6. Hold state mode (latch previous state)
-7. I/O Mode Control Override during Power-up
-8. Direct connection to pad is accessible to the core through ESD resistor and bypassing ESD resistor
-9. O/P configuration to drive the PAD in hold mode
+.. contents:: :local:
+ :depth: 1
.. [1] I/O (:cell:`sky130_fd_io__gpio`, :cell:`sky130_fd_io__gpiosf`, :cell:`sky130_fd_io__gpiov2`, :cell:`sky130_fd_io__gpio_ovtv2`, SIO).
