chore: fix some typos in comments (#2340)

Signed-off-by: alongdate <alongyear@outlook.com>

examples/global.rs

@@ -48,7 +48,7 @@ fn Display() -> Element {
 
 #[component]
 fn Reset() -> Element {
-    // Not all write methods are availale on global signals since `write` requires a mutable reference. In these cases,
+    // Not all write methods are available on global signals since `write` requires a mutable reference. In these cases,
     // We can simply pull out the actual signal using the signal() method.
     let mut as_signal = use_hook(|| COUNT.signal());