Update README.md

Author: wangjiawen2013

README.md

@@ -50,7 +50,7 @@ Add to `Cargo.toml`:
 [dependencies]
 charton = "0.5"                                         # Standard (Single-threaded)
 charton = { version = "0.5", features = ["parallel"] }  # Multi-threaded processing
-charton = { version = "0.5", features = ["resvg"] }     # With PNG support
+charton = { version = "0.5", features = ["png"] }     # With PNG support
 charton = { version = "0.5", features = ["bridge"] }    # With Altair/Matplotlib interop
 ```