Update readme a bit

README.md

@@ -4,10 +4,17 @@ packages.
 On RPM based distributions you must install the salt-debuginfo and gdb system
 packages.
 
-Once you have the pre-requisists find the top level Salt process and pass it's
-PID to the dbg.py script using Salt's python interpreter.
+relenv-dbg will gather some general debugging information as well as the stack traces from each thread.
 
-/opts/saltstack/salt/bin/python3 ./dbg.py <PID>
+/opts/saltstack/extras-3.10/bin/relenv-dbg <pid>
 
-The dbg.py script will use gdb to run gdb-command.txt the PID and all of it's
-child processes. The output is saved to gdb-output.txt.
+relenv-inject can be used to inject some python code into the running process.
+
+If you have manhole installed you can write a script like this:
+
+```manhole.py
+import manhole
+manhole.install()
+```
+
+/opts/saltstack/extras-3.10/bin/relenv-dbg <pid> manhole.py