Fix documentation: Options to observe method (#260)

Also fix leftovers from sampleRate to sampleInterval.
Fixes #259

CHANGES.md

@@ -73,6 +73,27 @@ function pressureCallback(update) {
   }
 }
 
-const observer = new PressureObserver(pressureCallback, { sampleInterval : 1000 });
+const observer = new PressureObserver(pressureCallback, { sampleInterval : 1_000 });
 observer.observe('cpu');
 ```
+### After (Release in Chrome M125)
+
+sampleRate was renamed to sampleInterval and changed from Hz to ms.[issue #253](https://github.com/w3c/compute-pressure/issues/253);
+Options are moved to the observe method. [issue #259] (https://github.com/w3c/compute-pressure/issues/259);
+
+
+[The explainer](https://github.com/w3c/compute-pressure/blob/main/README.md) and
+[specification](https://www.w3.org/TR/compute-pressure/) capture the latest vision for the API,
+implemented for further experimentation.
+
+```js
+function pressureCallback(update) {
+  if (update.status === "critical") {
+    // Dramatically cut down compute requirements to avoid overheating.
+    return;
+  }
+}
+
+const observer = new PressureObserver(pressureCallback);
+observer.observe('cpu',  { sampleInterval : 1_000 });
+```

HOWTO.md

@@ -30,10 +30,10 @@ function pressureObserverCallback(updates) {
 }
 
 // Create observer with 1000ms sample interval.
-observer = new PressureObserver(pressureObserverCallback, { sampleInterval: 1000 });
+observer = new PressureObserver(pressureObserverCallback);
 
 // Start observer.
-await observer.observe("cpu");
+await observer.observe("cpu", { sampleInterval: 1_000 });
 ```
 
 You should see, everytime the state changes, the following:

README.md

@@ -273,8 +273,8 @@ function callback(entries) {
   console.log(`Current pressure ${lastEntry.state}`);
 }
 
-const observer = new PressureObserver(callback, { sampleInterval: 1000 }); // 1000ms
-await observer.observe("cpu");
+const observer = new PressureObserver(callback);
+await observer.observe("cpu", {sampleInterval: 1_000 }); // 1000ms
 ```
 
 ## Key scenarios
@@ -356,8 +356,8 @@ function pressureChange(entries) {
   }
 }
 
-const observer = new PressureObserver(pressureChange, { sampleInterval: 1000 });
-await observer.observe("cpu");
+const observer = new PressureObserver(pressureChange);
+await observer.observe("cpu", { sampleInterval: 1_000 });
 ```
 
 ## Detailed design discussion