Add documentation on how to perform a major version update
Summary of changes
Initial generation done with claude/code using:
Create a markdown document in docs/devlopment called UpdatingTheSdk.md that describes how to do a version-bump upgrade for the version of the .NET SDK that we use in the repository. It should provde a high level description of all the things you need to do when doing a major version upgrade, pointing to relevant files where appropriate. It should also note when a change is only required if you're doing a major version upgrade of the SDK; not all changes will be required for minor version bumps of the SDK. It should also note anything you need to do differently between updates to stable versions, and updates to pre-release versions. You can find examples of previous commits which made all the necessary changes in the git history. For example, commits efc961d99bf5d8e35284b5130721f5fd3bbd64bf and e28bbab20d50a0b20fa7b283c44dd68307833b61 did minor version bumps, 9c46186aa518c33811f49beba26fc5b15558de49 and cb339ee505060fb3f39365b6322646eea1bbab65 did major version bumps, and def72805d23a4638a4dd527ece13998ad3c33862 did a version bump to a pre-release version. When looking back at this data, you'll need to remember that the repository may have changed significantly for commits made a long time ago. Create a high-level document first for me to review, and then we can fill in the details afterwards.