Add Fluxor .NET to integrations docs

[mrpmorris]

Fluxor - https://github.com/mrpmorris/Fluxor
Fluxor.Blazor.Web.ReduxDevTools - https://github.com/mrpmorris/Fluxor/tree/master/Source/Tutorials/02-Blazor/02D-ReduxDevToolsTutorial