[Pundit] Add Pundit for Permissions

[ShehrozIrfan]

Need to add Pundit for permission to the below actions of comment:

• Edit
• Update
• Delete

in such a way that, a user can only apply the above actions to the comments created by that user.

Relevant Links:

• Pundit official documentation
• Example implementation

[ShehrozIrfan]

#58