[docs] Updated documentation for api changes.

ReadMe.md

@@ -1,8 +1,7 @@
 ## Aeternum
 
-This is a very small C program that will daemonize any process on a Linux
-system.  All command line arguments aside from the name of the program to execute are passed
-through to the child.
+`aeternum` is a very small program that should daemonize any process on a Linux
+system.  
 
 ### Installation
 
@@ -15,6 +14,13 @@ This should make `aeternum` available on your PATH.
 
 ### Usage
 
-     aeternum [program] [args...]
+     aeternum -o [outfile] -e [errfile] -- [program] [args...]
 
+`outfile` is a file path to which the program's `stdout` should be redirected.
 
+`errfile` is a file path to which `stderr` should be redirected.
+
+If either is not provided, `/dev/null` will be used.
+
+The `--` option is used to delimit `aeternum` arguments from arguments to the
+process being spawned.  Everything after `--` will be passed to `execvp()`.