PreloadAfterLoad should use "prefetch"

[onlinebizsoft]

Is your feature request related to a problem? Please describe.
This is to improve performance of loading and increase pagespeed score
Describe the solution you'd like
For preloaAfterLoad should append to head as "prefetch" án browser will load during idle cpu which is better than loading agressively.
Describe alternatives you've considered
Additional context
Cc @aFarkas thanks for the great plugin
⚠️ Consider that most features can be solved by the simple plugin architecture and that most features doesn't need to be added to the core.