Rewrite Internal projects section

Rewrites the Internal projects section pretty much from scratch:

Blog has been slightly updated to remove some reference content that would be better moved to Notion. Instead, we now talk about the blog at a higher level.
Playbook has been updated to include some history about the playbook, when and how to contribute to it, and what the main differences are with Notion.
Company culture has been added. It talks about the processes the directors follow to make policy changes and adjustments about the company.
Solidus has been added. It talks about our role in the Solidus ecosystem and how it aligns with our vision.

I also added the new webcam to the Benefits section, while I was at it.

Latest commit:	`1c82683`
Status:	✅ Deploy successful!
Preview URL:	https://067cfaf8.playbook.pages.dev

nebulab / playbook