Support for standard md line to split request/response

[dahernan]

Support for lines in the way of --- instead of === to split request/response

Original example is

# Forgot your password

## POST /users

Create a new user.

{
    "name": "Test user",
    "username": "testreset",
    "email": "testreset@test.test.com",
    "password": "abc123",
    "password_confirm": "abc123"
}

===

Standard MD will be:

# Forgot your password

## POST /users

Create a new user.

{
    "name": "Test user",
    "username": "testreset",
    "email": "testreset@test.test.com",
    "password": "abc123",
    "password_confirm": "abc123"
}

---