Add initial project structure with basic view models, views, and resources

CryptoPortfolio Tracker/Views/MainView.axaml

@@ -0,0 +1,17 @@
+<NavigationPage xmlns="https://github.com/avaloniaui"
+                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+                xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+                xmlns:vm="using:CryptoPortfolio_Tracker.ViewModels"
+                xmlns:behaviors="clr-namespace:CryptoPortfolio_Tracker.Behaviors"
+                mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+                x:Class="CryptoPortfolio_Tracker.Views.MainView"
+                x:DataType="vm:MainViewModel"
+                behaviors:WindowDragBehavior.EnableWindowDrag="True">
+    <Design.DataContext>
+        <!-- This only sets the DataContext for the previewer in an IDE,
+             to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
+        <vm:MainViewModel />
+    </Design.DataContext>
+    
+</NavigationPage>