Enable doc_cfg for docs.rs in iced_glow

glow/Cargo.toml

@@ -30,3 +30,7 @@ path = "../native"
 version = "0.1"
 path = "../graphics"
 features = ["font-source", "font-fallback", "font-icons", "opengl"]
+
+[package.metadata.docs.rs]
+rustdoc-args = ["--cfg", "docsrs"]
+all-features = true

glow/src/lib.rs

@@ -6,6 +6,7 @@
 #![deny(missing_debug_implementations)]
 #![deny(unused_results)]
 #![forbid(rust_2018_idioms)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 mod backend;
 mod program;