clarify instructions regarding using a crate without registering

README.md

@@ -11,13 +11,23 @@ This index (and, by extension, the [crates.jstrong.dev] registry) allows crates
 How to use this index ?
 -----------------------
 
-If you want to use this index, you can follow these steps:
+If you want to use a crate hosted at [crates.jstrong.dev]:
 
 - Edit or create the `~/.cargo/config` file, and add the following code:
 ```toml
 [registries.jstrong-dev]
 index = "https://git.jstrong.dev/jstrong/crate-index"
 ```
+- In `Cargo.toml`, specify the crate's registry when declaring it as a dependency, e.g.:
+```toml
+[dependencies]
+markets = { version = "0.3.0", registry = "jstrong-dev" }
+```
+
+If you also want to publish a crate to the registry:
+
+- Register as a user at [crates.jstrong.dev]
+- Configure `~/.cargo/config` with `registries.jstrong-dev` entry as described above
 - Then, run `cargo login --registry jstrong-dev` and enter your author token.
 - You can now use the registry using `cargo publish --registry jstrong-dev` or `cargo search --registry jstrong-dev`