add more image extensions to PointImage test regex

[functorism]

Just adds a few more common image extensions to the test regex in PointImage.

    function isImgUrl(string) {
      let url;
      try {
        url = new URL(string);
      } catch (_) {
        return false;
      }
      if (url) {
        return /\.(jpg|jpeg|png|webp|bmp|gif|ico|svg)$/.test(url.pathname);
      }
      return false;
    }

[functorism]

Merge?

[timvisee]

I'll do so. Thanks for your work on this, and the bump!