Add MISRA.md and CHANGELOG.md files; minor update in README.md (#40)

CHANGELOG.md

@@ -0,0 +1,7 @@
+# Changelog for coreSNTP Library
+
+## v1.0.0 (July 2021)
+
+This is the first release of an coreSNTP client library in this repository.
+
+This library implements an SNTP client for the [SNTPv4 specification](https://tools.ietf.org/html/rfc4330). It is optimized for resource-constrained devices, and does not allocate any memory.

MISRA.md

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+# MISRA Compliance
+
+The coreSNTP library files conform to the [MISRA C:2012](https://www.misra.org.uk)
+guidelines, with some noted exceptions. Compliance is checked with Coverity static analysis.
+Deviations from the MISRA standard are listed below:
+
+### Ignored by [Coverity Configuration](https://github.com/aws/aws-iot-device-sdk-embedded-C/blob/main/tools/coverity/misra.config)
+| Deviation | Category | Justification |
+| :-: | :-: | :-: |
+| Directive 4.9 | Advisory | Allow inclusion of function like macros. The `assert` macro is used throughout the library for parameter validation, and logging is done using function like macros. |
+| Rule 2.4 | Advisory | Allow unused tags. Some compilers warn if types are not tagged. |
+| Rule 2.5 | Advisory | Allow unused macros. Library headers may define macros intended for the application's use, but are not used by a specific file. |
+| Rule 3.1 | Required | Allow nested comments. C++ style `//` comments are used in example code within Doxygen documentation blocks. |
+| Rule 11.5 | Advisory | Allow casts from `void *`. The library casts the byte array information received network to a `SntpPacket_t *` for parsing SNTP packet. |
+
+### Flagged by Coverity
+| Deviation | Category | Justification |
+| :-: | :-: | :-: |
+| Rule 8.7 | Advisory | API functions are not used by the library outside of the files they are defined; however, they must be externally visible in order to be used by an application. |
+
+### Suppressed with Coverity Comments
+*None.*

README.md

@@ -4,7 +4,7 @@ This repository contains the coreSNTP library, a client library to use Simple Ne
 
 An SNTP client can request time from both NTP and SNTP servers. According to the SNTPv4 specification, "_To an NTP or SNTP server, NTP and SNTP clients are indistinguishable; to an NTP or SNTP client, NTP and SNTP servers are indistinguishable._", thereby, allowing SNTP clients to request time from NTP servers.
 
-This library has gone through code quality checks including verification that no function has a [GNU Complexity](https://www.gnu.org/software/complexity/manual/complexity.html) score over 8, and checks against deviations from mandatory rules in the [MISRA coding standard](https://www.misra.org.uk). This library has also undergone both static code analysis from [Coverity static analysis](https://scan.coverity.com/), and validation of memory safety through the [CBMC automated reasoning tool](https://www.cprover.org/cbmc/).
+This library has gone through code quality checks including verification that no function has a [GNU Complexity](https://www.gnu.org/software/complexity/manual/complexity.html) score over 8, and checks against deviations from mandatory rules in the [MISRA coding standard](https://www.misra.org.uk). Deviations from the MISRA C:2012 guidelines are documented under [MISRA Deviations](MISRA.md). This library has also undergone both static code analysis from [Coverity static analysis](https://scan.coverity.com/), and validation of memory safety through the [CBMC automated reasoning tool](https://www.cprover.org/cbmc/).
 
 ## Cloning this repository
 This repo uses [Git Submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules) to bring in dependent components.