docs: Remove "Sealevel" from the introduction page and minor improvements (#3160)

docs/src/pages/index.md

@@ -1,10 +1,10 @@
 ---
 title: Introduction
 pageTitle: Anchor - Introduction
-description: Anchor is a framework for Solana's Sealevel runtime providing several convenient developer tools for writing smart contracts.
+description: Anchor is a framework for building secure Solana programs, often called 'smart contracts'.
 ---
 
-Anchor is a framework for Solana's Sealevel runtime providing several convenient developer tools for writing smart contracts. {% .lead %}
+Anchor is a framework for quickly building secure Solana programs.{% .lead %}
 
 {% link-grid %}
 
@@ -22,11 +22,10 @@ Anchor is a framework for Solana's Sealevel runtime providing several convenient
 
 ## What is Anchor
 
-Anchor is a framework for quickly building secure Solana programs.
+With Anchor you can quickly build secure Solana programs, sometimes called 'smart contracts', because: 
 
-With Anchor you can build programs quickly because it writes various boilerplate for you such as (de)serialization of accounts and instruction data.
-
-You can build secure programs more easily because Anchor handles certain security checks for you. On top of that, it allows you to succinctly define additional checks and keep them separate from your business logic.
+ - Anchor writes various boilerplate for you such as (de)serialization of accounts and instruction data.
+ - Anchor handles certain security checks for you, and allows you to succinctly define additional checks and keep them separate from your business logic.
 
 Both of these aspects mean that instead of working on the tedious parts of raw Solana programs, you can spend more time working on what matters most, your product.