Add XML docs

YesNt.Interpreter/Enums/SearchMode.cs

@@ -1,9 +1,19 @@
 namespace YesNt.Interpreter.Enums;
 
+/// <summary>
+/// Determines where in a source line the interpreter searches for a statement keyword.
+/// </summary>
 public enum SearchMode
 {
+    /// <summary>The keyword must appear at the beginning of the line.</summary>
     StartOfLine,
+
+    /// <summary>The keyword must appear at the end of the line.</summary>
     EndOfLine,
+
+    /// <summary>The keyword may appear anywhere in the line.</summary>
     Contains,
+
+    /// <summary>The entire line must exactly match the keyword.</summary>
     Exact
 }