Remove MainSite from PR template

Author: bart-vmware

.github/PULL_REQUEST_TEMPLATE.md

@@ -15,6 +15,6 @@ Fixes #{bug number}
 - [ ] Your code complies with our [Coding Style](https://github.com/SteeltoeOSS/.github/blob/main/contributing-docs/contributing-code-style.md).
 - [ ] You've updated unit and/or integration tests for your change, where applicable.
 - [ ] You've updated documentation for your change, where applicable.
-      If your change affects other repositories, such as [Documentation](https://github.com/SteeltoeOSS/Documentation), [Samples](https://github.com/SteeltoeOSS/Samples) and/or [MainSite](https://github.com/SteeltoeOSS/MainSite), add linked PRs here.
+      If your change affects other repositories, such as [Documentation](https://github.com/SteeltoeOSS/Documentation) and/or [Samples](https://github.com/SteeltoeOSS/Samples), add linked PRs here.
 - [ ] There's an open issue for the PR that you are making. If you'd like to propose a new feature or change, please open an issue to discuss the change or find an existing issue.
 - [ ] You've added required license files and/or file headers (explaining where the code came from with proper attribution), where code is copied from StackOverflow, a blog, or OSS.