Use cSpell spell check, and use ubuntu-20.04 for formatting check

.github/.cSpellWords.txt

@@ -1,8 +1,25 @@
+CBMC
+CBOR
 CMOCK
 CMock
 Cmock
 Coverity
+DCMOCK
+DDisable
+DNDEBUG
+DUNITY
 MISRA
+MQTT
 Misra
+Wunused
+abcdefghijklmno
+acceptedklmno
+cbmc
+cbor
+cmock
 coverity
+ctest
+lcov
 misra
+sinclude
+utest

.github/workflows/ci.yml

@@ -73,11 +73,11 @@ jobs:
       - name: Clone This Repo
         uses: actions/checkout@v3
       - name: Run spellings check
-        uses: FreeRTOS/CI-CD-GitHub-Actions/rust-spell-check@v2
+        uses: FreeRTOS/CI-CD-GitHub-Actions/spellings@v2
         with:
           path: ./
   formatting:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v3
       - name: Check formatting

README.md

@@ -1,6 +1,6 @@
 # AWS IoT Device Shadow library
 
-The AWS IoT Device Shadow library enables you to store and retrieve the current state (the “shadow”) of every registered device. The device’s shadow is a persistent, virtual representation of your device that you can interact with from AWS IoT Core even if the device is offline. The device state is captured as its “shadow” within a [JSON](https://www.json.org/) document. The device can send commands over MQTT to get, update and delete its latest state as well as receive notifications over MQTT about changes in its state. Each device’s shadow is uniquely identified by the name of the corresponding “thing”, a representation of a specific device or logical entity on the AWS Cloud. See [Managing Devices with AWS IoT](https://docs.aws.amazon.com/iot/latest/developerguide/iot-thing-management.html) for more information on IoT "thing". More details about AWS IoT Device Shadow can be found in [AWS IoT documentation](https://docs.aws.amazon.com/iot/latest/developerguide/iot-device-shadows.html). This library is distributed under the [MIT Open Source License](LICENSE). 
+The AWS IoT Device Shadow library enables you to store and retrieve the current state (the “shadow”) of every registered device. The device’s shadow is a persistent, virtual representation of your device that you can interact with from AWS IoT Core even if the device is offline. The device state is captured as its “shadow” within a [JSON](https://www.json.org/) document. The device can send commands over MQTT to get, update and delete its latest state as well as receive notifications over MQTT about changes in its state. Each device’s shadow is uniquely identified by the name of the corresponding “thing”, a representation of a specific device or logical entity on the AWS Cloud. See [Managing Devices with AWS IoT](https://docs.aws.amazon.com/iot/latest/developerguide/iot-thing-management.html) for more information on IoT "thing". More details about AWS IoT Device Shadow can be found in [AWS IoT documentation](https://docs.aws.amazon.com/iot/latest/developerguide/iot-device-shadows.html). This library is distributed under the [MIT Open Source License](LICENSE).
 
 **Note**: From [v1.1.0](https://github.com/aws/Device-Shadow-for-AWS-IoT-embedded-sdk/tree/v1.1.0) release onwards, you can used named shadow, a feature of the AWS IoT Device Shadow service that allows you to create multiple shadows for a single IoT device.