update readme (add gateway arg)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "livebox-exporter-rs"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

README.md

@@ -86,6 +86,7 @@ Supported command-line options (hope `-P` vs `-p` not to confusing):
 | -P, --password <password> | Livebox password **(required)**                 | None          |
 | -p, --port <port>         | Exporter port                                 | 9100          |
 | -l, --listen <address>    | Listen address                                | 0.0.0.0       |
+| -G, --gateway <address>   | Livebox gateway ip address                    | 192.168.1.1   |
 | -v, --verbose             | Enable verbose logging (repeat for increased verbosity) | Off     |
 | -h, --help                | Display help message                         | N/A           |
 
@@ -97,6 +98,7 @@ Options:
   -l, --listen <address>     listen address [default: 0.0.0.0]
   -v, --verbose...           verbose logging
   -P, --password <password>  Livebox password [required]
+  -G, --gateway <gateway>    Livebox gateway ip address [default: 192.168.1.1]
   -h, --help                 Print help
   -V, --version              Print version
 ```

src/main.rs

@@ -383,7 +383,7 @@ mod tests {
             "-P",
             "mypassword",
             "-G",
-            "192.168.1.10"
+            "192.168.1.10",
         ];
         let matches = parse_args(args);
         assert_eq!(