Adding API endpoints

[nikoescobal]

In this PR, I did the following:

• Create an API endpoint to list all posts.
• Create an API endpoint to list all comments for a post.
• Create an API endpoint to add a comment to a post. Remember that the owner of the comment is the user that makes it; it should not be set by passing a parameter.
• Add authentication to your API endpoints.
• Ensure API endpoints receive JSON and respond with JSON as well.

[SajjadAhmad14]

Hi Niko, 

While you made a great effort in this project, unfortunately, I cannot proceed to review your code.

## Invalid Code Review Request

You have submitted a project, that does not follow Git flow. Please see [this](https://github.com/microverseinc/curriculum-transversal-skills/blob/main/git-github/articles/gitflow.md) link and follow Git flow. 

Your Code Review Request will be marked as invalid in your Dashboard, so please submit a new one once you are ready 🙏

Cheers and Happy coding!👏👏👏

Feel free to leave any questions or comments in the PR thread if something is not 100% clear.

**_Please, do not open a new Pull Request for re-reviews. You should use the same Pull Request submitted for the first review, either valid or invalid unless it is requested otherwise._**

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[nikoescobal]

@SajjadAhmad14 I've left a message on Slack to explain the situation. Please do check.

[AshakaE]

Hi @nikoescobal 🙋‍♀️,

STATUS APPROVED ✔

Your project is complete! There is nothing else to say other than... it's time to merge it 🔗 🚢
Congratulations! 🎉

Optional suggestions

Every comment with the [OPTIONAL] prefix won't stop the approval of this PR. However, I strongly recommend you to take them into account as they can make your code better. Some of them were simply missed by the previous reviewer and addressing them will really improve your application.

Cheers 🥂 and Happy coding!👏👏👏

Feel free to leave any questions or comments in the PR thread if something is not 100% clear.

Please, do not open a new Pull Request for re-reviews. You should use the same Pull Request submitted for the first review, either valid or invalid unless it is requested otherwise.

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