XamarinEmbededImgResource.cs

using System;
using System.Reflection;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace HeVibrates
{
    [ContentProperty (nameof(Source))]
    class ImageResourceExtension:IMarkupExtension
    {
        public string Source { get; set; }
        public object ProvideValue(IServiceProvider serviceProvider)
        {
            if (Source == null) return null;

            var imgSource = ImageSource.FromResource(Source, typeof(ImageResourceExtension).GetTypeInfo().Assembly);
            return imgSource;
        }
    }
}

//xmlns:local ="clr-namespace:PROJECTNAME"
//<Image Source="{local:ImageResource Source=PROJCETNAME.IMAGEPATH}"/>

//IMAGEPATH = Folder.Image.png