Add a new section for "Fundamentals of Block Development"

[juanmaguitar]

The purpose of this subsection of "Getting Started" chapter is to surface the knowledge needed to start and understand block development. This pages cover the pain points received from developers about aspects not being clear when starting learning about block development in issues like #22151

This is the diagram used for the outline with the key ideas for each page

• Getting Started > Fundamentals of Block Development > Anatomy of a block #55437
• Getting Started > Fundamentals of Block Development > block.json #55944
• Getting Started > Fundamentals of Block Development > Registration of a block #55943
• Getting Started > Fundamentals of Block Development > Storing data in block's attributes  #55945
• Getting Started > Fundamentals of Block Development > The block in the editor - edit #56273
• Getting Started > Fundamentals of Block Development > Using built-in components #55946
• Getting Started > Fundamentals of Block Development > Static or Dynamic rendering of a block #56274
• Getting Started > Fundamentals of Block Development > Markup's representation of a block #56271
• Getting Started > Fundamentals of Block Development > Styling blocks #56275
• Getting Started > Fundamentals of Block Development > Lifecycle of the block #56276
• Getting Started > Fundamentals of Block Development > Javascript in the Block Editor #56277