Adding exam to week 5
Fix exam file to folder
Adding basic Passport task
Adding Linking Accounts task
Exam is week4 not week5

- Rename everything
Fixing typos & Adding social login buttons
Merge https://github.com/HackBulgaria/NodeJS-1
Clarify domain restriction for sitemap builder
Fix convolution usage example
Merge https://github.com/HackBulgaria/NodeJS-1
Exam 1 solutions added