Query and display pinned post

[monacodelisa]

Describe the solution you'd like
There is a property to query for pinned posts, you should:

• investigate how to get the pinned post
• use the property to show the pinned post before any other posts within the posts component
• NOT in the series component
• explore options of displaying the pinned post
• again a good starting point is seeing how it is done in Hashnode
• suggestions are welcome - it may be larger than the rest of the posts, but it must be discussed first,
• you can propose implementation by changing styles in chrome dev tools and sharing a screenshot
• do not submit implementation that has not been approved since the PR will be automatically rejected.