Fix typo in web-sys.mdx (#3790) [skip ci]

Author: dlachaume

website/versioned_docs/version-0.18.0/concepts/wasm-bindgen/web-sys.mdx

@@ -129,7 +129,7 @@ document.getElementById('mousemoveme').onmousemove = (e) => {
 
 ### `web-sys` example
 
-Using `web-sys` alone the above JavaSciprt example could be implemented like this:
+Using `web-sys` alone the above JavaScript example could be implemented like this:
 
 ```toml title=Cargo.toml
 [dependencies]

website/versioned_docs/version-0.21/concepts/basic-web-technologies/web-sys.mdx

@@ -145,7 +145,7 @@ document.getElementById('mousemoveme').onmousemove = (e) => {
 
 ### `web-sys` example
 
-Using `web-sys` alone the above JavaSciprt example could be implemented like this:
+Using `web-sys` alone the above JavaScript example could be implemented like this:
 
 ```toml title=Cargo.toml
 [dependencies]