message: [pdsl_core] Update storage module documentation
diff: //!
  //! These are the new primitives for contract storage access and their provided guarantees.
  //!
  -//! | Primitive | Owned | Typed | Opt. Reads | Mutable | Safe Load | Requirements |
  -//! |:-----------:|:-----:|:-----:|:----------:|:-------:|:---------:|:-------------|
  -//! | `Key` | No | No | No | No | No | |
  -//! | `RawCell` | Yes | No | No | No | No | |
  -//! | `TypedCell` | Yes | Yes | No | No | No | |
  -//! | `SnycCell` | Yes | Yes | Yes | Yes | No | |
  +//! | Primitive | Owned | Typed | Opt. Reads | Mutable | Safe Load |
  +//! |:-----------:|:-----:|:-----:|:----------:|:-------:|:---------:|
  +//! | `Key` | No | No | No | No | No |
  +//! | `RawCell` | Yes | No | No | No | No |
  +//! | `TypedCell` | Yes | Yes | No | No | No |
  +//! | `SyncCell` | Yes | Yes | Yes | Yes | No |
  //!
  //! ## Chunks
  //!
  