Rename CODE_OF_CONDUCT extension to lower case (#11791)

* Rename CODE_OF_CONDUCT.MD to CODE_OF_CONDUCT.md

Apparently the extension needs to be lower-case for it to be recognized by GitHub

* Update case of links to CODE_OF_CONDUCT.md

Co-authored-by: Michael Curran <mick@nvaccess.org>

.github/ISSUE_TEMPLATE.md

@@ -9,7 +9,7 @@ Direct links to the templates:
 Please thoroughly read NVDA's wiki article on how to fill in this template, including how to provide the required files.
 Issues may be closed if the required information is not present.
 https://github.com/nvaccess/nvda/wiki/Github-issue-template-explanation-and-examples
-Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.MD. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
+Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.md. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
 -->
 
 ### Steps to reproduce:

.github/ISSUE_TEMPLATE/bug_report.md

@@ -8,7 +8,7 @@ about: Create a report to help us improve
 Please thoroughly read NVDA's wiki article on how to fill in this template, including how to provide the required files.
 Issues may be closed if the required information is not present.
 https://github.com/nvaccess/nvda/wiki/Github-issue-template-explanation-and-examples
-Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.MD. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
+Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.md. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
 -->
 
 ### Steps to reproduce:

.github/ISSUE_TEMPLATE/feature_request.md

@@ -8,7 +8,7 @@ about: Suggest an idea for this project
 Please thoroughly read NVDA's wiki article on how to fill in this template, including how to provide the required files.
 Issues may be closed if the required information is not present.
 https://github.com/nvaccess/nvda/wiki/Github-issue-template-explanation-and-examples
-Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.MD. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
+Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.md. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
 -->
 
 ### Is your feature request related to a problem? Please describe.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,6 +1,6 @@
 <!-- Please read and fill in the following template, for an explanation of the sections see:
 https://github.com/nvaccess/nvda/wiki/Github-pull-request-template-explanation-and-examples
-Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.MD. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
+Please also note that the NVDA project has a Citizen and Contributor Code of Conduct which can be found at https://github.com/nvaccess/nvda/blob/master/CODE_OF_CONDUCT.md. NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project. This includes creating or commenting on issues and pull requests. 
 -->
 
 ### Link to issue number:

readme.md

@@ -4,7 +4,7 @@ NVDA (NonVisual Desktop Access) is a free, open source screen reader for Microso
 It is developed by NV Access in collaboration with a global community of contributors.
 To learn more about NVDA or download a copy, visit the main [NV Access](http://www.nvaccess.org/) website.
 
-Please note: the NVDA project has a [Citizen and Contributor Code of Conduct](CODE_OF_CONDUCT.MD). NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project.
+Please note: the NVDA project has a [Citizen and Contributor Code of Conduct](CODE_OF_CONDUCT.md). NV Access expects that all contributors and other community members read and abide by the rules set out in this document while participating or contributing to this project.
 
 ## Get support
 Either if you are a beginner, an advanced user, a new or a long time developer, or if you are an organization willing to know more or to contribute to NVDA, you can get support through the documentation in place as well as several communication channels dedicated for the NVDA screen reader. Here is an overview of the most important support sources.