Add EciMode comments

Author: Shane32

QRCoder/QRCodeGenerator.EciMode.cs

@@ -2,11 +2,34 @@
 {
     public partial class QRCodeGenerator
     {
+        /// <summary>
+        /// Enumerates the Extended Channel Interpretation (ECI) modes used in QR codes to handle different character encoding standards.
+        /// ECI mode allows QR codes to efficiently encode data using character sets other than the default ISO-8859-1.
+        /// </summary>
         public enum EciMode
         {
+            /// <summary>
+            /// Default encoding mode (typically ISO-8859-1). Used when no ECI mode is explicitly specified.
+            /// This mode is assumed in basic QR codes where no extended character sets are needed.
+            /// </summary>
             Default = 0,
+
+            /// <summary>
+            /// Specifies the use of the ISO-8859-1 character set, covering most Western European languages.
+            /// This mode explicitly sets the encoding to ISO-8859-1, which includes characters used in languages such as English, French, German, and Spanish.
+            /// </summary>
             Iso8859_1 = 3,
+
+            /// <summary>
+            /// Specifies the use of the ISO-8859-2 character set, which is primarily used for Central and Eastern European languages.
+            /// This includes characters used in languages such as Polish, Czech, Slovak, Hungarian, and Romanian.
+            /// </summary>
             Iso8859_2 = 4,
+
+            /// <summary>
+            /// Specifies the use of UTF-8 encoding.
+            /// UTF-8 can encode any Unicode character and is useful for QR codes that need to support multi-language content.
+            /// </summary>
             Utf8 = 26
         }
     }