chore: add text demo

example/text.js

@@ -0,0 +1,33 @@
+const { promises } = require('fs')
+const { join } = require('path')
+const { performance } = require('perf_hooks')
+
+const { Resvg } = require('../index')
+
+async function main() {
+  const svg = `
+  <svg xmlns="http://www.w3.org/2000/svg" width="200" height="200" viewBox="0 0 200 200">
+    <text fill="blue" font-family="sans-serif" font-size="120">
+      <tspan x="40" y="143">水</tspan>
+    </text>
+  </svg>
+  `
+  const opts = {
+    background: '#fff',
+    font: {
+      fontFiles: ['./example/SourceHanSerifCN-Light-subset.ttf'], // Load custom fonts.
+      loadSystemFonts: false, // It will be faster to disable loading system fonts.
+      defaultFontFamily: 'Source Han Serif CN Light',
+    },
+    logLevel: 'debug', // Default Value: error
+  }
+  const t = performance.now()
+  const resvg = new Resvg(svg, opts)
+  const pngData = resvg.render()
+  const pngBuffer = pngData.asPng()
+  console.info('✨ Done in', performance.now() - t, 'ms')
+
+  await promises.writeFile(join(__dirname, './text2-out.png'), pngBuffer)
+}
+
+main()