Excluded demo.gif from crate

Author: Rehan Ali Rana

Cargo.toml

@@ -9,6 +9,9 @@ repository = "https://github.com/RAR27/dyn-wall-rs"
 readme = "README.md"
 keywords = ["dynamic", "wallpaper"]
 categories = ["command-line-utilities"]
+exclude = [ 
+    "demo.gif"
+]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html