add pattern explanation to readme

readme.md

@@ -9,3 +9,21 @@ cargo install cargo-vibe
 ```shell
 cargo vibe build
 ```
+
+# Configuration
+
+By default, `cargo-vibe` will, on success, vibe full strength for 3 seconds.
+
+You can change that by setting `CARGO_VIBE_PATTERN` environment variable. For
+example, to set it vibe for 1.5 second on 20% strength, you can do:
+
+```shell
+CARGO_VIBE_PATTERN="0.2 1.5s" cargo vibe <cmd>
+```
+
+You can also set full patterns of vibes to run, by separating them with slashes
+`/`. Here is one example:
+
+```
+CARGO_VIBE_PATTERN="0.4 1s/0.6 1s/0.8 0.75s/1.0 0.25s"
+```

src/main.rs

@@ -41,10 +41,10 @@ fn parse_pattern(
         .split('/')
         .map(|x| {
             let (speed, duration) =
-                x.split_once(" ").ok_or("couldn't split")?;
+                x.split_once(' ').ok_or("couldn't split")?;
             let speed = speed.parse()?;
             let duration = duration
-                .strip_suffix("s")
+                .strip_suffix('s')
                 .ok_or("missing 's'")?
                 .parse()
                 .map(Duration::from_secs_f64)?;