style: add image to figure plugin

- Improve styles for images, blockquotes, tables and more
- Fix unexpected line breaks

src/plugins/remark-reading-time.mjs

@@ -0,0 +1,13 @@
+import { toString } from 'mdast-util-to-string'
+import getReadingTime from 'reading-time'
+
+export function remarkReadingTime() {
+  return (tree, { data }) => {
+    const textOnPage = toString(tree)
+    const readingTime = getReadingTime(textOnPage)
+    data.astro.frontmatter.minutes = Math.max(
+      1,
+      Math.round(readingTime.minutes),
+    )
+  }
+}