Upgrade to .Net 5

[taooceros]

.Net 5 has released. Should we upgrade the project to .Net 5?

[jjw24]

yep we should, but the main goal at the moment is to fix up and improve the plugin model, and address the high memory/cpu issue #128.

Since we are on .Net Core 3.1, we should be pretty prepped for .Net 5.

[taooceros]

Yes, I have taken a try on updating, not too hard to do the job except changing part of the configuration file for browser bookmark and websearch, and updating the modernwpf package.

[jjw24]

yeah cool. I meant feel free to work on which ever enhancements you like, just for myself though I will be giving time priority to those above main areas of focus.

[taooceros]

Yes sure, of course we should spend more time on the more important things. Just to mark a potential future improvement.