Better readme

README.md

@@ -17,6 +17,24 @@ npm install -g diagrams
 
 # Usage
 
+## watch
+The diagrams CLI provides the `watch` command that will automatically generate the .svg visualization of each diagram file format it supports. Run the following:
+
+Watches the current directory and generates an .svg file in the same directory as any found file.
+```
+diagrams watch
+```
+
+Same as above but also first generates all .svg files before starting watch process
+```
+diagrams watch --build
+```
+
+To provide the target directory to watch just pass it as an argument right after the `watch` command.
+```
+diagrams watch somedirectory --build
+```
+
 ## flowchart
 Documentation: [Flowchart.js ](http://flowchart.js.org/).