Revise "Introduction"

Ontology is a new generation of high-performance public blockchains. The infrastructure is scalable, stable, and allows low-level customization for different business requirements. After the Ontology MainNet release, we have welcomed many new developers to the Ontology technical community and launched our Developer Center .

https://dev-docs.ont.io/#/docs-en/DeveloperGuide/introduction

Expected

An intro which mentions the key characteristics of Ontology

The very detailed graphic which sholws internal subsystems, should be replaced by a "Grand Ontology Subsystems Overview"