fix(guide): simplify directory structure

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

@@ -0,0 +1,30 @@
+---
+title: Where
+---
+
+# Where
+
+Filters elements from the dataset.
+
+### Signature
+```csharp
+Enumerable.Where<TSource> Method (IEnumerable<TSource>, Func<TSource, Boolean>)
+```
+
+## 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   }
+};
+
+// Fruits with more than 3 items
+var moreThanThree = fruits.Where(f => f.Quantity > 3).ToList(); // { Strawberry, Grape, Apple }
+
+// Fruits that are not red
+var notRed = fruits.Where(f => f.Color != "Red").ToList(); // { Orange, Grape, Pineapple, Mango }
+```