Support ZSTD compression method for reading (#256)

Cargo.toml

@@ -20,10 +20,14 @@ exclude = ["tests/images/*", "tests/fuzz_images/*"]
 weezl = "0.1.0"
 jpeg = { package = "jpeg-decoder", version = "0.3.0", default-features = false }
 flate2 = "1.0.20"
+zstd = { version = "0.13", optional = true }
 
 [dev-dependencies]
 criterion = "0.3.1"
 
+[features]
+zstd = ["dep:zstd"]
+
 [[bench]]
 name = "lzw"
 harness = false