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/15-javagc/README.md

@@ -4,6 +4,8 @@ eBPF (Extended Berkeley Packet Filter) is a powerful network and performance ana
 
 In this article of our eBPF Tutorial by Example series, we will explore how to use eBPF and USDT to capture and analyze the duration of Java garbage collection (GC) events.
 
+> The complete source code: <https://github.com/eunomia-bpf/bpf-developer-tutorial/tree/main/src/15-javagc>
+
 ## Introduction to USDT
 
 USDT is a mechanism for inserting static tracepoints into applications, allowing developers to insert probes at critical points in the program for debugging and performance analysis purposes. These probes can be dynamically activated at runtime by tools such as DTrace, SystemTap, or eBPF, allowing access to the program's internal state and performance metrics without the need to restart the application or modify the program code. USDT is widely used in many open-source software applications such as MySQL, PostgreSQL, Ruby, Python, and Node.js.