Add required documents

Author: Leah-Xia-Microsoft

CHANGELOG.md

@@ -19,15 +19,13 @@ contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additio
  - [Submission Guidelines](#submit)
 
 ## <a name="purpose"></a>Sample App Purpose
-Sample apps are built to help showcase the capabilities of Azure Communication Services. 
+Sample apps are built to help showcase the capabilities of Azure Communication Services.
 This app uses all best practices and follows limitations related to the service.
 As you contribute make sure to follow service guidelines or your work might not be accepted.
 The app is built on top of the existing Azure Communiation Services SDKs, and will not diverge from the capabilities offered by the SDK.
-This means that if the feature desired is not supported on the SDK, please don't try to hack it into the sample. 
+This means that if the feature desired is not supported on the SDK, please don't try to hack it into the sample.
 
-The sample is continously updated as new features are added to the underlying SDKs and feel free to contribute any features that are supported.
-In the case of the chat app, two samples are available, one on the `main` branch and another on the `public-preview` branch. 
-If the feature you are looking to add is currently in `public preview`, meaning it is only available on `beta` packages, make sure to contribute to the correct branch.
+The sample is continuously updated as new features are added to the stable version of the underlying SDKs and feel free to contribute any features that are supported.
 
 ## <a name="coc"></a> Code of Conduct
 Help us keep this project open and inclusive. Please read and follow our [Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
@@ -63,12 +61,12 @@ chances of your issue being dealt with quickly:
 * **Suggest a Fix** - if you can't fix the bug yourself, perhaps you can point to what might be
   causing the problem (line of code or commit)
 
-You can file new issues by providing the above information at the corresponding repository's issues link: https://github.com/[organization-name]/[repository-name]/issues/new].
+You can file new issues by providing the above information at the corresponding repository's issues link: https://github.com/Azure-Samples/communication-services-web-chat-hero/issues/new.
 
 ### <a name="submit-pr"></a> Submitting a Pull Request (PR)
 Before you submit your Pull Request (PR) consider the following guidelines:
 
-* Search the repository (https://github.com/[organization-name]/[repository-name]/pulls) for an open or closed PR
+* Search the repository (https://github.com/Azure-Samples/communication-services-web-chat-hero/pulls) for an open or closed PR
   that relates to your submission. You don't want to duplicate effort.
 
 * Make your changes in a new git fork:

CONTRIBUTING.md

@@ -0,0 +1,41 @@
+<!-- BEGIN MICROSOFT SECURITY.MD V0.0.9 BLOCK -->
+
+## Security
+
+Microsoft takes the security of our software products and services seriously, which includes all source code repositories managed through our GitHub organizations, which include [Microsoft](https://github.com/Microsoft), [Azure](https://github.com/Azure), [DotNet](https://github.com/dotnet), [AspNet](https://github.com/aspnet) and [Xamarin](https://github.com/xamarin).
+
+If you believe you have found a security vulnerability in any Microsoft-owned repository that meets [Microsoft's definition of a security vulnerability](https://aka.ms/security.md/definition), please report it to us as described below.
+
+## Reporting Security Issues
+
+**Please do not report security vulnerabilities through public GitHub issues.**
+
+Instead, please report them to the Microsoft Security Response Center (MSRC) at [https://msrc.microsoft.com/create-report](https://aka.ms/security.md/msrc/create-report).
+
+If you prefer to submit without logging in, send email to [secure@microsoft.com](mailto:secure@microsoft.com).  If possible, encrypt your message with our PGP key; please download it from the [Microsoft Security Response Center PGP Key page](https://aka.ms/security.md/msrc/pgp).
+
+You should receive a response within 24 hours. If for some reason you do not, please follow up via email to ensure we received your original message. Additional information can be found at [microsoft.com/msrc](https://www.microsoft.com/msrc). 
+
+Please include the requested information listed below (as much as you can provide) to help us better understand the nature and scope of the possible issue:
+
+  * Type of issue (e.g. buffer overflow, SQL injection, cross-site scripting, etc.)
+  * Full paths of source file(s) related to the manifestation of the issue
+  * The location of the affected source code (tag/branch/commit or direct URL)
+  * Any special configuration required to reproduce the issue
+  * Step-by-step instructions to reproduce the issue
+  * Proof-of-concept or exploit code (if possible)
+  * Impact of the issue, including how an attacker might exploit the issue
+
+This information will help us triage your report more quickly.
+
+If you are reporting for a bug bounty, more complete reports can contribute to a higher bounty award. Please visit our [Microsoft Bug Bounty Program](https://aka.ms/security.md/msrc/bounty) page for more details about our active programs.
+
+## Preferred Languages
+
+We prefer all communications to be in English.
+
+## Policy
+
+Microsoft follows the principle of [Coordinated Vulnerability Disclosure](https://aka.ms/security.md/cvd).
+
+<!-- END MICROSOFT SECURITY.MD BLOCK -->