Do not echo in add_leadin_frontend_scripts

Hi,

Your plugin breaks the WP REST API responses, because in /inc/class-leadin.php you are printing the following:

echo '<!-- HubSpot WordPress Plugin v' . LEADIN_PLUGIN_VERSION . ': embed JS disabled as a portalId has not yet been configured -->';

Please remove that line, because it’s printed in every rest response and we get
SyntaxError: Unexpected token < in JSON at position 0 SyntaxError: Unexpected token < in JSON at position 0, because that line is printed before the json.

It’s not a good idea to print something, when using wp_enqueue_scripts hook.

Please use any other hook like wp_add_inline_style or admin_head.

Regards,
Stanimir