Update README.md (#3)

README.md

@@ -3,4 +3,16 @@ Apache SkyWalking CLI
 
 <img src="http://skywalking.apache.org/assets/logo.svg" alt="Sky Walking logo" height="90px" align="right" />
 
-The CLI for [Apache SkyWalking](https://github.com/apache/skywalking).
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+The CLI (Command Line Interface) for [Apache SkyWalking](https://github.com/apache/skywalking).
+
+SkyWalking CLI is a command interaction tool for the SkyWalking user or OPS team, as an alternative besides using browser GUI.
+It is based on SkyWalking [GraphQL query protocol](https://github.com/apache/skywalking-query-protocol), same as GUI.
+
+# Commands
+TODO
+
+# Compiling project
+TODO
+
+# License
+[Apache 2.0 License.](/LICENSE)