add English doc (#55)

* add english documents

* docs: add root english README

src/27-replace/README_en.md

@@ -0,0 +1,36 @@
+# Replace Text Read or Written by Any Program with eBPF 
+
+Compile:
+
+```bash
+make
+```
+
+Usage:
+
+```sh
+sudo ./replace --filename /path/to/file --input foo --replace bar
+```
+
+This program will replace all text in the file that matches 'input' with 'replace' text.
+There are many use cases for this, such as:
+
+Hiding the kernel module 'joydev' to avoid detection by tools like 'lsmod':
+
+```bash
+./replace -f /proc/modules -i 'joydev' -r 'cryptd'
+```
+
+Spoofing the MAC address of the 'eth0' interface:
+
+```bash
+./replace -f /sys/class/net/eth0/address -i '00:15:5d:01:ca:05' -r '00:00:00:00:00:00'
+```
+
+Malware performing anti-sandbox checks may look for MAC addresses as an indication of whether it is running in a virtual machine or sandbox, rather than on a "real" machine.
+
+**Note:** The lengths of 'input' and 'replace' must be the same to avoid introducing NULL characters in the middle of the text block. To input a newline character at a bash prompt, use `$'\n'`, for example `--replace $'text\n'`.
+
+## References
+
+- <https://github.com/pathtofile/bad-bpf>.