adding decompress middleware

Author: Arun Gopalpuri

website/content/middleware/decompress.md

@@ -0,0 +1,41 @@
++++
+title = "Decompress Middleware"
+description = "Decompress middleware for Echo"
+[menu.main]
+  name = "Decompress"
+  parent = "middleware"
++++
+
+Decompress middleware decompresses HTTP request if Content-Encoding header is set to gzip.
+
+*Usage*
+
+`e.Use(middleware.Decompress())`
+
+## Custom Configuration
+
+*Usage*
+
+```go
+e := echo.New()
+e.Use(middleware.DecompressWithConfig(middleware.DecompressConfig{
+  Skipper: Skipper
+}))
+```
+
+## Configuration
+
+```go
+DecompressConfig struct {
+  // Skipper defines a function to skip middleware.
+  Skipper Skipper
+}
+```
+
+*Default Configuration*
+
+```go
+DefaultDecompressConfig = DecompressConfig{
+  Skipper: DefaultSkipper,
+}
+```