Verify every feature on CI #4698

• Replace https://github.com/sindresorhus/refined-github/pull/4495

This workflow should be replaced by a simple node script that ensures:

• only .tsx and .css files exist in /features/
• getFeaturesMeta matches the tsx files in /features/ exactly and is full
• each file appears in refined-github.tsx

Pseudo-code:

const featuresFromReadme = getFeaturesMeta()

for (const file of featuresDirectory) {
    if (file.extension === 'css' || file === 'index.tsx') {
        continue;
    }

    if (!featuresFromReadme[file]) {
        throw error
    }

    if (featuresFromReadme[file].description.length < 20) {
        throw error too short
    }

    if (refinedGithubTex.includes(`import "./features/${file.name}"`) {
        throw error;
    }
}

Ideally written in a way that it can report multiple errors, for example by replacing the throw with console.error + a variable that will mark the run as failed.