Add check and release scripts.

Had to slightly adjust package names to make this work.

substreams/check.sh

@@ -0,0 +1,6 @@
+set -e
+
+cargo +nightly fmt -- --check
+cargo +nightly clippy --all --all-features --all-targets -- -D warnings
+cargo build --target wasm32-unknown-unknown --all-targets --all-features
+cargo test --workspace --all-targets --all-features