Clean up dated README notice

Author: workingjubilee

README.md

@@ -1,16 +1,3 @@
-# The Crates.io Version Can No Longer Be Updated!
-
-The original maintainer is out of contact, and the new maintainers (the Portable SIMD Project Group) do not have the appropriate crates.io permissions to issue updates.
-
-We are aware that the version available on crates.io is currently broken, and will not build.
-
-If you need to continue to use the crate, we have published a "next version" under an alternative name.
-
-Adjust your `[dependencies]` section of `Cargo.toml` to be the following:
-```toml
-packed_simd = { version = "0.3.8", package = "packed_simd" }
-```
-
 # `Simd<[T; N]>`
 
 ## Implementation of [Rust RFC #2366: `std::simd`][rfc2366]