feat: Add markdown doc based on app's openapi specification

[Iito]

This feat adds the possibility to generate the documentation of an app in Markdown (git style).
Beautifully named fastapi doc
It uses from fastapi.openapi.utils.get_openapi to generate the openapi specs then turn those specs into markdown.

Here is an example of generated doc based on FastAPI's example

from typing import Union

from fastapi import FastAPI

app = FastAPI(title="MyFirstAPI")


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}

Generated doc:

MyFirstAPI

Version: 0.1.0

Paths

/

GET

Summary: Read Root

Operation ID: read_root__get

Responses:

Status Code	Description	Content
200	Successful Response	application/json: schema: [A](#a)

/items/{item_id}

GET

Summary: Read Item

Operation ID: read_item_items__item_id__get

Parameters:

Name	In	Required	Schema	Description	Example
item_id	path	True	type: integer title: Item Id	N/A	N/A
q	query	False	type: N/A title: Q	N/A	N/A
Responses:

Status Code	Description	Content
200	Successful Response	application/json: schema: [A](#a)
422	Validation Error	application/json: schema: [HTTPValidationError](#httpvalidationerror)

Components

Schemas

HTTPValidationError

• Type: object
• Title: HTTPValidationError
• Properties:
  • detail:
    • Type: array
    • Title: Detail
    • Description: N/A

ValidationError

• Type: object
• Required: loc, msg, type
• Title: ValidationError
• Properties:
  • loc:
    • Type: array
    • Title: Location
    • Description: N/A
  • msg:
    • Type: string
    • Title: Message
    • Description: N/A
  • type:
    • Type: string
    • Title: Error Type
    • Description: N/A