docs: add complete source code links to various eBPF tutorial README files

src/35-user-ringbuf/README.md

@@ -4,7 +4,9 @@ eBPF, or Extended Berkeley Packet Filter, is a revolutionary technology in the L
 
 One unique aspect of eBPF is that it not only allows programs to run in kernel mode to access low-level system states and resources, but it can also communicate with user mode programs through special data structures. One important concept in this regard is the ring buffer between kernel mode and user mode. In many real-time or high-performance applications, the ring buffer is a commonly used data structure. Due to its FIFO (first in, first out) characteristics, data can flow continuously and linearly between the producer and the consumer, avoiding frequent IO operations and unnecessary memory reallocation overhead.
 
-In eBPF, two types of ring buffers are provided: user ring buffer and kernel ring buffer, to achieve efficient data communication between user mode and kernel mode. This article is part of the eBPF developer tutorial. More detailed content can be found here: <https://eunomia.dev/tutorials/> The source code is open source in the <https://github.com/eunomia-bpf/bpf-developer-tutorial>.
+In eBPF, two types of ring buffers are provided: user ring buffer and kernel ring buffer, to achieve efficient data communication between user mode and kernel mode. This article is part of the eBPF developer tutorial. More detailed content can be found here: <https://eunomia.dev/tutorials/> 
+
+> The complete source code: <https://github.com/eunomia-bpf/bpf-developer-tutorial/tree/main/src/35-user-ringbuf>
 
 ## User mode and kernel mode ring buffers—user ring buffer and kernel ring buffer