fix(guide): simplify directory structure

guide/english/csharp/linq/select/index.md

@@ -0,0 +1,28 @@
+---
+title: Select
+---
+
+# Select
+
+Projects data from the data set.
+
+### Signature
+```csharp
+Enumerable.Select<TSource, TResult> Method (IEnumerable<TSource>, Func<TSource, TResult>)
+```
+
+## Example
+```csharp
+var fruits = new List<Fruit>() {
+    new Fruit() { Id = 1, Name = "Orange",     Color = "Orange", Quantity = 3   },
+    new Fruit() { Id = 2, Name = "Strawberry", Color = "Red",    Quantity = 12  },
+    new Fruit() { Id = 3, Name = "Grape",      Color = "Purple", Quantity = 25  },
+    new Fruit() { Id = 4, Name = "Pineapple",  Color = "Yellow", Quantity = 1   },
+    new Fruit() { Id = 5, Name = "Apple",      Color = "Red",    Quantity =  5   },
+    new Fruit() { Id = 6, Name = "Mango",      Color = "Yellow", Quantity = 2   }
+};
+
+var mangoQnt = fruits.Where(f => f.Name == "Mango").Select(f => f.Quantity).FirstOrDefault(); // 2
+
+var grapeColor = fruits.Where(f => f.Name == "Grape").Select(f => f.Color).FirstOrDefault(); // Purple
+```