chore: Make this plugin as official (#441)

Co-authored-by: Daniel M. Capella <polyzen@users.noreply.github.com>

Author: baseballyama

README.md

@@ -1,6 +1,6 @@
 # Introduction
 
-`eslint-plugin-svelte` is [ESLint] plugin for [Svelte].  
+`eslint-plugin-svelte` is the official [ESLint] plugin for [Svelte].  
 It provides many unique check rules by using the template AST.  
 You can check on the [Online DEMO](https://sveltejs.github.io/eslint-plugin-svelte/playground/).
 
@@ -23,12 +23,6 @@ You can check on the [Online DEMO](https://sveltejs.github.io/eslint-plugin-svel
 [ESLint] plugin for [Svelte].  
 It provides many unique check rules using the AST generated by [svelte-eslint-parser].
 
-### ❓ Why?
-
-[Svelte] has the official [ESLint] plugin the [eslint-plugin-svelte3]. The [eslint-plugin-svelte3] works well enough to check scripts. However, it does not handle the AST of the template, which makes it very difficult for third parties to create their own the [ESLint] rules for the [Svelte].
-
-The [svelte-eslint-parser] aims to make it easy to create your own rules for the [Svelte] by allowing the template AST to be used in the rules.
-
 ### ❗ Attention
 
 The [svelte-eslint-parser] and the `eslint-plugin-svelte` can not be used with the [eslint-plugin-svelte3].

docs/README.md

@@ -4,7 +4,7 @@ title: "eslint-plugin-svelte"
 
 # Introduction
 
-`eslint-plugin-svelte` is [ESLint] plugin for [Svelte].  
+`eslint-plugin-svelte` is the official [ESLint] plugin for [Svelte].  
 It provides many unique check rules by using the template AST.  
 You can check on the [Online DEMO](./playground.md).
 
@@ -27,12 +27,6 @@ You can check on the [Online DEMO](./playground.md).
 [ESLint] plugin for [Svelte].  
 It provides many unique check rules using the AST generated by [svelte-eslint-parser].
 
-### ❓ Why?
-
-[Svelte] has the official [ESLint] plugin the [eslint-plugin-svelte3]. The [eslint-plugin-svelte3] works well enough to check scripts. However, it does not handle the AST of the template, which makes it very difficult for third parties to create their own the [ESLint] rules for the [Svelte].
-
-The [svelte-eslint-parser] aims to make it easy to create your own rules for the [Svelte] by allowing the template AST to be used in the rules.
-
 ### ❗ Attention
 
 The [svelte-eslint-parser] and the `eslint-plugin-svelte` can not be used with the [eslint-plugin-svelte3].