WebSharper.JQuery 5.0.0-preview1

This is a preview release of WebSharper.JQuery 5.

Features

• #2 Split out JQuery from Core repository into it's own repository.
• #5 Move Ajax/AjaxWith methods from Core's WebSharper.Sitelets.Router into this repository. Same fully qualified name.
• #7 Added .NET 5 support. .NET Core 3.1 and netstandard2.0 still supported.
• #7 Use common Build script with WebSharper ecosystem.

Enhancements

• #3 Added Tests for JQuery.