Add HID-BPF tutorial and implementation for virtual mouse input modification

- Introduced a comprehensive tutorial in README.md explaining how to fix broken HID devices using eBPF without kernel patches.
- Implemented a userspace program (hid-input-modifier.c) that creates a virtual HID mouse using the uhid interface and sends synthetic mouse events.
- Developed a BPF program (hid-input-modifier.bpf.c) that intercepts HID events and modifies mouse movement data, effectively doubling the X and Y movement.
- Created necessary header files (hid_bpf.h, hid_bpf_defs.h, hid_bpf_helpers.h) to define structures and helper functions for the BPF program.
- Added functionality to find and manage the virtual HID device, ensuring seamless integration with the BPF program.

src/13-tcpconnlat/README.md

@@ -4,6 +4,8 @@ eBPF (Extended Berkeley Packet Filter) is a powerful network and performance ana
 
 This article is the thirteenth installment of the eBPF Tutorial by Example, mainly about how to use eBPF to statistics TCP connection delay and process data in user space using libbpf.
 
+> The complete source code: <https://github.com/eunomia-bpf/bpf-developer-tutorial/tree/main/src/13-tcpconnlat>
+
 ## Background
 
 When developing backends, regardless of the programming language used, we often need to call databases such as MySQL and Redis, perform RPC remote calls, or call other RESTful APIs. The underlying implementation of these calls is usually based on the TCP protocol. This is because TCP protocol has advantages such as reliable connection, error retransmission, congestion control, etc., so TCP is more widely used in network transport layer protocols than UDP. However, TCP also has some drawbacks, such as longer connection establishment delay. Therefore, some alternative solutions have emerged, such as QUIC (Quick UDP Internet Connections).