Fix broken example links

[mikeyzhong]

For any example if you click the code link it leads to a broken page.

e.g. https://sparkjs.dev/examples/#particle-simulation

[mrxz]

Thanks, this addresses #328.

With your changes the URLs aren't normalized, so it might be cleaner to do the following:

- codeButton.href = `https://github.com/sparkjsdev/spark/blob/main/examples/${path}`;
+ codeButton.href = new URL(`https://github.com/sparkjsdev/spark/blob/main/examples/${path}`).toString();

[mikeyzhong]

Thanks, made the change.

[dmarcos]

Thanks so much!