Allow setting heapless feature on serde_at with atat feature. (#201)

README.md

@@ -109,7 +109,8 @@ The following dependent crates provide platform-agnostic device drivers built on
 - `log`: Disabled by default. Enable log statements on various log levels to aid debugging. Powered by `log`.
 - `defmt`: Disabled by default. Enable defmt log statements on various log levels to aid debugging. Powered by `defmt`.
 - `custom-error-messages`: Disabled by default. Allows errors to contain custom error messages up to 64 characters, parsed by `AtDigest::custom_error`.
-- `hex_str_arrays`: Disabled by default. Needs `#![feature(generic_const_exprs)]` Nightly feature. This allows for hex strings to be serialized to a fix-width byte array. 
+- `hex_str_arrays`: Disabled by default. Needs `#![feature(generic_const_exprs)]` Nightly feature. This allows for hex strings to be serialized to a fix-width byte array.
+- `heapless`: Enable heapless feature on `serde_at`. This enables heapless support and adds some specialized parsing structs.
 
 ## Chat / Getting Help
 

atat/Cargo.toml

@@ -52,3 +52,4 @@ bytes = ["heapless-bytes", "serde_bytes"]
 custom-error-messages = []
 std = ["serde_at/std", "nom/std", "embassy-time/std", "embedded-io/std"]
 hex_str_arrays = []
+heapless = ["serde_at/heapless"]