Misorganized Tests Folders

[ovflowd]

On this repository tests are spread on a different amount of folders:

• https://github.com/nodejs/api-docs-tooling/tree/main/src/test
• https://github.com/nodejs/api-docs-tooling/tree/main/src/utils/tests
• ...

I think at the very least we could follow the website repo and standardise the folder names, maybe all under __tests__