build: add @vue/runtime-dom as devDependency

[setchy]

Description

Add @vue/runtime-dom as devDependency

Addressed Issue

Resolves VSCode / Vue Doctor warning

@vue/runtime-dom missing for Vue 2
Vue 2 does not have JSX type definitions, so template type checking will not work correctly. You can resolve this problem by installing @vue/runtime-dom and adding it to your project's devDependencies.

Additional Details

Checklist

• I have read and understand the contributing guidelines
• This PR introduces new or alters existing behavior, and I have updated the documentation accordingly