ElectronNET.API: Move API code to subfolder

src/ElectronNET.API/API/Entities/ThemeSourceMode.cs

@@ -0,0 +1,28 @@
+using System.ComponentModel;
+
+namespace ElectronNET.API.Entities
+{
+    /// <summary>
+    /// Defines the ThemeSourceMode enumeration.
+    /// </summary>
+    public enum ThemeSourceMode
+    {
+        /// <summary>
+        /// Operating system default.
+        /// </summary>
+        [Description("system")]
+        System,
+
+        /// <summary>
+        /// Light theme.
+        /// </summary>
+        [Description("light")]
+        Light,
+
+        /// <summary>
+        /// Dark theme.
+        /// </summary>
+        [Description("dark")]
+        Dark
+    }
+}