message: Update ContributingGuidelines.md
  to fix broken link and stale content
diff: -### Please refer to the [`wiki`](https://github.com/Azure/adx-documentation-pr/wiki) for internal contribution guidelines.
  -[`Link your GitHub account`](https://repos.opensource.microsoft.com/) to the 'Azure' organization for access.
  +For internal contributor, for management plane, please refer to https://aka.ms/rpguidelines;
  +
  +For data-plane, please refer to [Guide to design and creation of Data Plane REST API and Client Libraries](https://dev.azure.com/azure-sdk/internal/_wiki/wikis/internal.wiki/591/Guide-to-design-and-creation-of-Data-Plane-REST-API-and-Client-Libraries);
  +
  +For contribution access to spec repos, please refer to [Public repo vs. Private repo: To get write access](https://dev.azure.com/azure-sdk/internal/_wiki/wikis/internal.wiki/202/Overall-Process-of-Management-Plane-SDK-Onboarding?anchor=2.-create/update-the-openapi-specifications%2C-and-launch-swagger-pr-review)
  