Update README

README.md

@@ -11,6 +11,7 @@ Currently, DBG requires the following [patch](https://codereview.appspot.com/117
 ### Features
 
 * Attach to (trace) a running process
+* Ability to launch a process and begin debugging it
 * Set breakpoints
 * Single step through a process
 * Next through a process (step over / out of subroutines)
@@ -18,6 +19,18 @@ Currently, DBG requires the following [patch](https://codereview.appspot.com/117
 
 ### Usage
 
+The debugger can be launched in two ways:
+
+* Provide the name of the program you want to debug, and the debugger will launch it for you.
+	
+	$ dbg -proc path/to/program
+
+* Provide the pid of a currently running process, and the debugger will attach and begin the session.
+
+	$ dbg -pid 44839
+
+Once inside a debugging session, the following commands may be used:
+
 * `break` - Set break point at the entry point of a function, or at a specific file/line. Example: `break foo.go:13`.
 
 * `step` - Single step through program.