docs(README): add OUR SUPPORT POLICY section

twada · twada · commit 560b349e9e4e · 2016-11-15T17:22:00.000+09:00
diff --git a/README.md b/README.md
@@ -97,6 +97,15 @@ Detection is done by [escallmatch](https://github.com/twada/escallmatch). Any ar
 See [CHANGELOG](https://github.com/power-assert-js/gulp-espower/blob/master/CHANGELOG.md)
 
 
+## OUR SUPPORT POLICY
+
+We support Node under maintenance. In other words, we stop supporting old Node version when [their maintenance ends](https://github.com/nodejs/LTS).
+
+This means that any other environment is not supported.
+
+NOTE: If espower-cli works in any of the unsupported environments, it is purely coincidental and has no bearing on future compatibility. Use at your own risk.
+
+
 ## AUTHOR
 
 * [Takuto Wada](https://github.com/twada)
