Improve readme page in crates.io (#11809)

Author: lewiszlw

datafusion/core/Cargo.toml

@@ -20,7 +20,7 @@ name = "datafusion"
 description = "DataFusion is an in-memory query engine that uses Apache Arrow as the memory model"
 keywords = ["arrow", "query", "sql"]
 include = ["benches/*.rs", "src/**/*.rs", "Cargo.toml"]
-readme = "README.md"
+readme = "../../README.md"
 version = { workspace = true }
 edition = { workspace = true }
 homepage = { workspace = true }