[BUG] PHP generates bad links in Model docs

[jacobweber]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

Using the PHP generator, it creates files like docs/Model/*.md. They have links at the bottom like "Back to README", which point to "..", but they should point to "../..". The links in docs/Api are correct.

openapi-generator version

4.0.0-SNAPSHOT

OpenAPI declaration file content or url

Any

Command line used for generation

Anything with -g php.

Steps to reproduce

View sample client:
https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/samples/client/petstore/php/OpenAPIClient-php/docs/Model/Dog.md

Related issues/PRs

N/A

Suggest a fix

Change .. to ../.. in template

[karismann]

i will send a PR

[jacobweber]

Thanks!