Add spark2

Author: jadnohra

crates/spark2/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "binius-spark2"
+version.workspace = true
+edition.workspace = true
+authors.workspace = true
+
+[dependencies]
+binius-core = { path = "../core" }
+binius-field = { path = "../field" }
+
+[dev-dependencies]
+
+[[example]]
+name = "keccak_chi"
+path = "examples/keccak_chi.rs"
+
+[[example]]
+name = "expression_demo"
+path = "examples/expression_demo.rs"