Expand the README a bit.

Author: ltratt

README.md

@@ -11,10 +11,18 @@ test command still succeeds. If it does, it keeps that visibility; otherwise it
 tries the next in the list. As this suggests, `depub` is destructive: it
 overwrites files, so do not run it on source code that you do not want altered!
 
-A standard way to run it is:
+For example, if you want to reduce visibility of a normal build, `cd` to your
+Rust code base and execute:
 
 ```
-$ cargo run depub -- -c "cargo check"
+$ /path/to/depub -- -c "cargo check"
+```
+
+The string specified with `-c` is passed straight to `/bin/sh` so can be any
+shell command. If you want to test multiple features you might use:
+
+```
+$ /path/to/depub -- -c "cargo check && cargo check --features f1"
 ```
 
 `depub` informs you of its progress. After it is finished, `diff` your code