Fix docs.rs build issues for eframe, egui-winit, egui_glium, egui_glow

I hope we can get rid of the `tts` crate very soon,
now that AcessKit has landed. It is only used for web atm.
Should probably be removed from all native libraries.

crates/egui-winit/Cargo.toml

@@ -14,7 +14,8 @@ keywords = ["winit", "egui", "gui", "gamedev"]
 include = ["../LICENSE-APACHE", "../LICENSE-MIT", "**/*.rs", "Cargo.toml"]
 
 [package.metadata.docs.rs]
-all-features = true
+# Avoid speech-dispatcher dependencies - see https://docs.rs/crate/egui-winit/0.20.0/builds/695196
+features = ["document-features"]
 
 
 [features]