Add best practice page for "Patches over instructions"

Description

Patches are the epitome of an actionable comment. They are also so much more consumable that blobs of text.

Let's add a page (something like /practices/patches-over-instructions) highlighting the best practice of leaving patches.

Points to hit

• Leaving a comment with a bunch of detailed instructions will create lots more back-and-forth because text is open to interpretation and is hard to digest.
• Patches are the ultimate of actionable comment (simply apply and go).
• Patches are a very effective way to mentor.
• Code speaks louder than words.

Ideally we would also mention that:

• Patches doesn't have to be limited to git or even code. The idea is to let the reader see real changes on top of their submission.