Update some links due to main branch renames (#6401)

Author: lbussell

.github/ISSUE_TEMPLATE/config.yml

@@ -13,7 +13,7 @@ contact_links:
     url: https://github.com/dotnet/sdk/issues/new/choose
     about: Please open issues relating to the .NET SDK itself in dotnet/sdk.
   - name: Issue with other .NET components
-    url: https://github.com/dotnet/core/blob/master/Documentation/core-repos.md
+    url: https://github.com/dotnet/core/blob/main/Documentation/core-repos.md
     about: Having issues with other .NET components? Please find the correct location where to open an issue.
   - name: Issue with Visual Studio Tools for Docker
     url: https://github.com/microsoft/dockertools/issues

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing
 
-See [dotnet/runtime Contributing](https://github.com/dotnet/runtime/blob/master/CONTRIBUTING.md) for information about coding styles, source structure, making pull requests, and more.
+See [dotnet/runtime Contributing](https://github.com/dotnet/runtime/blob/main/CONTRIBUTING.md) for information about coding styles, source structure, making pull requests, and more.
 
 ## General Feedback and Questions
 

README.md

@@ -26,7 +26,7 @@ You can use C# or F# to write .NET apps.
 
 [.NET](https://github.com/dotnet/core) is open source (MIT and Apache 2 licenses) and was contributed to the [.NET Foundation](http://dotnetfoundation.org) by Microsoft in 2014. It can be freely adopted by individuals and companies, including for personal, academic or commercial purposes. Multiple companies use .NET as part of apps, tools, new platforms and hosting services.
 
-You are invited to [contribute new features](https://github.com/dotnet/core/blob/master/CONTRIBUTING.md), fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.
+You are invited to [contribute new features](https://github.com/dotnet/core/blob/main/CONTRIBUTING.md), fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.
 
 > [.NET Documentation](https://docs.microsoft.com/dotnet/core/)
 

documentation/scenarios/installing-dotnet.md

@@ -118,7 +118,7 @@ By having the version of .NET you're installing explicitly defined in the Docker
 * .NET download URL (e.g. `ENV DOTNET_URL=https://download.visualstudio.microsoft.com/...`)
 * SHA value (e.g. `dotnet_sha512='d4d67df5ff5f6dde0d865a6e87559955bd57429df396cf7d05fe77f09e6220c67dc5e66439b1801ca4d301a62f81f666122bf4b623b31a46b861677dcafc62a4'`)
 
-You can track these values by making use of the information contained in the `releases.json` of the relevant release. For example, the [`releases.json`](https://builds.dotnet.microsoft.com/dotnet/release-metadata/9.0/releases.json) for 9.0 contains all the metadata for the 9.0 releases including download links of the binary archives as well as their hash values. The release information is described on the main [release notes](https://github.com/dotnet/core/blob/master/release-notes/README.md) page.
+You can track these values by making use of the information contained in the `releases.json` of the relevant release. For example, the [`releases.json`](https://builds.dotnet.microsoft.com/dotnet/release-metadata/9.0/releases.json) for 9.0 contains all the metadata for the 9.0 releases including download links of the binary archives as well as their hash values. The release information is described on the main [release notes](https://github.com/dotnet/core/blob/main/release-notes/README.md) page.
 
 ### Installing from a Linux Package Manager
 

documentation/supported-platforms.md

@@ -4,7 +4,7 @@ This document describes the platforms (OS and architectures) supported by the of
 
 ## Operating Systems
 
-.NET supports [a broad set of operating systems and versions](https://github.com/dotnet/core/blob/master/os-lifecycle-policy.md). When producing container images, it’s impractical to support the full matrix of OS, arch, and .NET version combinations. In practice, images are produced for a select set of operating systems and versions. If official .NET container images aren't provided for your preferred OS, [let us know by opening a discussion](https://github.com/dotnet/dotnet-docker/discussions). Alternatively, you can [author your own .NET images](scenarios/installing-dotnet.md).
+.NET supports [a broad set of operating systems and versions](https://github.com/dotnet/core/blob/main/os-lifecycle-policy.md). When producing container images, it’s impractical to support the full matrix of OS, arch, and .NET version combinations. In practice, images are produced for a select set of operating systems and versions. If official .NET container images aren't provided for your preferred OS, [let us know by opening a discussion](https://github.com/dotnet/dotnet-docker/discussions). Alternatively, you can [author your own .NET images](scenarios/installing-dotnet.md).
 
 - New versions of operating systems that we support are added on a best-effort basis, typically within one month.
 - New OSes are always available in the [nightly repositories](https://github.com/dotnet/dotnet-docker/blob/nightly/README.md) first, and then are added to the officially supported repos afterwards.

eng/readme-templates/About.product-family.md

@@ -9,6 +9,6 @@ You can use C# or F# to write .NET apps.
 
 [.NET](https://github.com/dotnet/core) is open source (MIT and Apache 2 licenses) and was contributed to the [.NET Foundation](http://dotnetfoundation.org) by Microsoft in 2014. It can be freely adopted by individuals and companies, including for personal, academic or commercial purposes. Multiple companies use .NET as part of apps, tools, new platforms and hosting services.
 
-You are invited to [contribute new features](https://github.com/dotnet/core/blob/master/CONTRIBUTING.md), fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.
+You are invited to [contribute new features](https://github.com/dotnet/core/blob/main/CONTRIBUTING.md), fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.
 
 > [.NET Documentation](https://docs.microsoft.com/dotnet/core/)