Update all docs links to 0.6, release 0.6 (#3225)

* update doc links to 0.6
* add new splash pages for crates
* update keyword features
* remove some unnecessary links

Cargo.toml

@@ -224,6 +224,7 @@ cargo-config2 = "0.1.26"
 criterion = { version = "0.5" }
 walrus = "0.23.2"
 cargo_metadata = "0.18.1"
+parking_lot = "0.12.1"
 tracing-wasm = "0.2.1"
 console_error_panic_hook = "0.1.7"