Add docs on how cargo-credential finds the action argument.

diff --git a/crates/credential/cargo-credential/src/lib.rs b/crates/credential/cargo-credential/src/lib.rs
index ae30b87d633815702c30ccbbfabb18b006798f6d..43dc0ba317635da859b39448658f129070baf503 100644 (file)
--- a/crates/credential/cargo-credential/src/lib.rs
+++ b/crates/credential/cargo-credential/src/lib.rs
@@ -8,6 +8,11 @@
 //!     cargo_credential::main(MyCredential);
 //! }
 //! ```
+//!
+//! This will determine the action to perform (get/store/erase) by looking at
+//! the CLI arguments for the first argument that does not start with `-`. It
+//! will then call the corresponding method of the trait to perform the
+//! requested action.
 
 pub type Error = Box<dyn std::error::Error>;