Update README.md

Author: koaj

README.md

@@ -1,2 +1,35 @@
 # apen
 Append from stdin to a new file.
+
+
+
+### Usage:
+
+
+```bash
+cat 1.txt
+one
+two
+two
+one
+```
+
+```bash
+cat 2.txt
+one
+line
+```
+
+```bash
+cat 1.txt | ./apen 2.txt
+two
+```
+
+```bash
+cat 2.txt
+one
+line
+two
+```
+
+Inspierd by [anew](https://github.com/tomnomnom/anew).