add README.md

nextzhou · nextzhou · commit 691b4592be6a · 2018-11-21T19:19:16.000+08:00
diff --git a/README.md b/README.md
@@ -0,0 +1,11 @@
+```
+$ t help
+Timestamp conversion tool
+
+Usage: t [time point]] [+|- <duration>...]...
+
+Time point format: all the usual format 😎
+
+Duration format: <Number><Unit>
+    Available duration units: y[ear], M[onth], d[ay], h[our], m[inute], s[econd]
+```
