Fix docs formatting - Githubissues

Description of the change

Terraform doc preview has a limitation that does not display nested list items correctly unless the tab width is equal to 4. This PR adds a prettier config to fix this.

Type of change

[x] Bug fix (non-breaking change that fixes an issue)
[ ] New feature (non-breaking change that adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklists

Development

[x] Lint rules pass locally
[ ] The code changed/added as part of this pull request has been covered with tests
[ ] All tests related to the changed code pass in development

Code review

[x] This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
[ ] Jira issue referenced in commit message and/or PR title

Testing

Tested by reviewing the changes and using the Terraform doc preview tool to verify that the docs are displayed correctly.

cyralinc / terraform-provider-cyral

Fix docs formatting #520