Include NVDA-VSCode as a Submodule (#17211)
Closes #17003
Summary of the issue:
The nvda-vscode repository exists to create a workspace configuration for VS Code that contains some sensible defaults, and recommendations for extensions that make developing for NVDA to our standards easier. However, using this workspace configuration currently requires manually clone it.
Description of user facing changes:
None
Description of developer-facing changes:
The .vscode directory for NVDA is now included as a submodule. This reduces friction for VS Code users, should have effectively no impact on users of other IDEs, and can be disabled by users who do not desire this behaviour.
Description of development approach:
Added nvaccess/vscode-nvda as a submodule. Set its ignore option to dirty so that users' changes to their project config don't cause the superproject to show as dirty. Updated the dev docs to note the change.
Testing strategy:
Verified that .gitmodules has been updated.
Known issues with pull request:
None.
