Intro and add an intro link
:toc:
:sectnums:
-== Intro
+== Intro in one sentence
-Next-generation framework for blockchain innovation.
+Substrate is a next-generation framework for blockchain innovation.
== Description
@@ -14,6 +14,8 @@ At its heart, Substrate is a combination of three technologies: WebAssembly, Lib
Substrate chains have three distinct features that make them "next-generation": a dynamic, self-defining state-transition function; light-client functionality from day one; and a progressive consensus algorithm with fast block production and adaptive, definite finality. The STF, encoded in WebAssembly, is known as the "runtime". This defines the `execute_block` function, and can specify everything from the staking algorithm, transaction semantics, logging mechanisms and procedures for replacing any aspect of itself or of the blockchain's state ("governance"). Because the runtime is entirely dynamic all of these can be switched out or upgraded at any time. A Substrate chain is very much a "living organism".
+See also https://www.parity.io/what-is-substrate/.
+
== Usage
Substrate is still an early stage project, and while it has already been used as the basis of major projects like Polkadot, using it is still a significant undertaking. In particular, you should have a good knowledge of blockchain concepts and basic cryptography. Terminology like header, block, client, hash, transaction and signature should be familiar. At present you will need a working knowledge of Rust to be able to do anything interesting (though eventually, we aim for this not to be the case).
