CHEF-26773 - Create CONTRIBUTING.md file with inactive template for habitat-sh

[Saburesh07]

This repo is being archived and is no longer accepting contributions. Create CONTRIBUTING.md file with standard template indicating that the repo has been archived and is no longer accepting contributions. This pull request Creates CONTRIBUTING.md file with the standard template for the inactive projects. As part of the repo standardization effort, when a repo is formally archived, we are replacing all the different contributing guides with a standard template that links to a message about archived repos. The link provided in the template may not function at the time this PR is opened, in which case this PR is intended to remain in Draft status if the repo permits; in any case it should not be merged until the link is live.