doc: Update LWN RCU API links in whatisRCU.rst

This commit adds the 2024 LWN RCU API article set.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>

Author: paulmckrcu

Documentation/RCU/whatisRCU.rst

@@ -15,6 +15,9 @@ to start learning about RCU:
 |	2014 Big API Table           https://lwn.net/Articles/609973/
 | 6.	The RCU API, 2019 Edition    https://lwn.net/Articles/777036/
 |	2019 Big API Table           https://lwn.net/Articles/777165/
+| 7.	The RCU API, 2024 Edition    https://lwn.net/Articles/988638/
+|       2024 Background Information  https://lwn.net/Articles/988641/
+|	2024 Big API Table           https://lwn.net/Articles/988666/
 
 For those preferring video: