Handle more various relative references

[jablko]

e.g.

• https://github.com/DefinitelyTyped/DefinitelyTyped/blob/0d8cc30feb7b4012c98886c8f0112b0a70548cd0/types/dwt/v13/dwt-tests.ts#L1
• https://github.com/DefinitelyTyped/DefinitelyTyped/blob/0d8cc30feb7b4012c98886c8f0112b0a70548cd0/types/slickgrid/test/slick.autotooltips.ts#L1
• https://github.com/DefinitelyTyped/DefinitelyTyped/blob/0d8cc30feb7b4012c98886c8f0112b0a70548cd0/types/react/test/experimental.tsx#L1
• https://github.com/DefinitelyTyped/DefinitelyTyped/blob/0d8cc30feb7b4012c98886c8f0112b0a70548cd0/types/webpack/test/next.ts#L1

[sandersn]

If I recall correctly, this rule is intentional; of the examples you linked to, only the nested reference in slickgrid should be allowed, so probably the change should be to require as many leading ../ as the number of nested directories + 1.

The others should be rewritten to the same form as the slickgrid reference.

(Same comments as other PRs about adding tests and moving to DefinitelyTyped-tools)