[BUG][SWIFT4][SWIFT5] Broken README templates

[iliaskarim]

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

The Swift4 and Swift5 generated README files appear broken.

Their overview sections end with, By using the [openapi-spec from a remote server, you can easily generate an API client.

openapi-generator version

4.3.0

OpenAPI declaration file content or url

Any OpenAPI spec will do, e.g. https://pastebin.com/raw/vqUT9yZN

Command line used for generation

java -jar openapi-generator-cli-4.3.0.jar generate -i openapi.json -g swift5 -o demo-openapi

Steps to reproduce

Generate a Swiff4/5 client with openapi-generator.

Related issues/PRs

None

Suggest a fix

The text should read, By using the [openapi-spec](https://github.com/OAI/OpenAPI-Specification) from a remote server, you can easily generate an API client.