check: Verify resource/data source file name matches page content title

[bflad]

Currently, there is no checking that the documentation file names line up to the resource or data source they are documenting. There should be a check that verifies the page content title matches the filename.

Will publish, but incorrect today (with resource file named thing.md):

---
# ... Frontmatter ...
---

# Resource: example_other_thing

Passing: resource file named other_thing.md (or page content title with example_thing)

[bflad]

Experimental support for this has been added via new -enable-contents-check flag in version 0.8.0 of tfproviderdocs.

[bflad]

This project will be archived in preference of the revamped validate command in github.com/hashicorp/terraform-plugin-docs implementing much of the basic validation logic from this project. Feature requests should be submitted over there at this point.