add English doc (#55)

* add english documents

* docs: add root english README

src/25-signal/README_en.md

@@ -0,0 +1,24 @@
+# Terminate Malicious Processes Using bpf_send_signal
+
+Compile:
+
+```bash
+make
+```
+
+Usage:
+
+```bash
+sudo ./bpfdos
+```
+
+This program sends a `SIG_KILL` signal to any program that tries to use the `ptrace` system call, such as `strace`.
+Once bpf-dos starts running, you can test it by running the following command:
+
+```bash
+strace /bin/whoami
+```
+
+## References
+
+- <https://github.com/pathtofile/bad-bpf>.