docs(valid-style-parse): documented the rule

docs/rules/valid-style-parse.md

@@ -0,0 +1,74 @@
+---
+pageClass: 'rule-details'
+sidebarDepth: 0
+title: 'svelte/valid-style-parse'
+description: 'require valid style element parsing'
+---
+
+# svelte/valid-style-parse
+
+> require valid style element parsing
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> **_This rule has not been released yet._** </badge>
+
+## :book: Rule Details
+
+This rule reports issues with parsing of the `<style>` element by the svelte-eslint-parser.
+
+<!--eslint-skip-->
+
+```svelte
+<script>
+  /* eslint svelte/valid-style-parse: ["error"] */
+</script>
+<!-- ✓ GOOD -->
+<style>
+  .class {
+    font-weight: bold;
+  }
+</style>
+```
+
+```svelte
+<script>
+  /* eslint svelte/valid-style-parse: ["error"] */
+</script>
+<!-- ✓ GOOD -->
+<style lang="scss">
+  .class {
+    font-weight: bold;
+  }
+</style>
+```
+
+```svelte
+<script>
+  /* eslint svelte/valid-style-parse: ["error"] */
+</script>
+<!-- ✗ BAD -->
+<style>
+  .class
+    font-weight: bold;
+</style>
+```
+
+```svelte
+<script>
+  /* eslint svelte/valid-style-parse: ["error"] */
+</script>
+<!-- ✗ BAD -->
+<style lang="unknown">
+  .class {
+    font-weight: bold;
+  }
+</style>
+```
+
+## :wrench: Options
+
+Nothing.
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/packages/eslint-plugin-svelte/src/rules/valid-style-parse.ts)
+- [Test source](https://github.com/sveltejs/eslint-plugin-svelte/blob/main/packages/eslint-plugin-svelte/tests/src/rules/valid-style-parse.ts)