docs: Refactor readme using structure from pact-js

[tienvx]

• Use structure from pact-js/pact-go
• There are no workshop for pact-php, so I remove that section
• Change version of platform windows x86 from All to 9.x - docs: platform support #600

[tienvx]

Self-reviewed

[mefellows]

Looks great Tien! 👏

Couple of minor comments - this needs a link:

Could format as code (minor):

Missing plugin documentation?

[tienvx]

• I fixed the link to installation.
• I created ticket for code formatting docs: Code block is not formatted #609
• Missing plugin documentation?
  • Yes. Currently I only move the existing document from readme to other pages. I didn't spend much time on reading document from other projects and make pact-php follow deeper structure.