Update AuthenticateService.php

[ivus]

just a spelling mistake

Description

The function subscriptionByChannelId didn't work properly. It was getting always the first 50 results and the user could not get more or less. The parameter 'maxResults' didn't do anything.

I reactivated the function parseSubscriptions and fixed it to get the desired amount of results instead of all of them.

To avoid confuision, the parameters is passed now as totalResults instead of maxResults since the last is the Google Api's parameter for each page, which can only be set up to 50

The Read Me was updated

Motivation and context

User was not able to get results off the first page

How has this been tested?

I listed my own channel subscriptions

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have read the CONTRIBUTING document.
• My pull request addresses exactly one patch/feature.
• I have created a branch for this patch/feature.
• Each individual commit in the pull request is meaningful.
• I have added tests to cover my changes.
• If my change requires a change to the documentation, I have updated it accordingly.