Add markdown preview, update rust.vim

sources_non_forked/markdown-preview.nvim/app/pages/image.js

@@ -0,0 +1,28 @@
+function resolveHtmlImage (tokens, idx) {
+  let content = tokens[idx].content || ''
+
+  content = content.replace(/<img\s+([^>]*?)src\s*=\s*(["'])([^\2>]+?)\2([^>]*)>/gm, (m, g1, g2, g3, g4) => {
+    if (/^(http|\/\/|data:)/.test(g3)) {
+      return m
+    }
+    return `<img ${g1}src="/_local_image_${encodeURIComponent(g3)}"${g4}>`
+  })
+
+  return content
+}
+
+function resolveImage (tokens, idx) {
+  const src = tokens[idx].attrs[0][1]
+  const alt = tokens[idx].content
+  const resAttrs = tokens[idx].attrs.slice(2).reduce((pre, cur) => `${pre} ${cur[0]}=${cur[1]}`, '')
+  if (/^(http|\/\/|data:)/.test(src)) {
+    return `<img src="${src}" alt="${alt}" ${resAttrs} />`
+  }
+  return `<img src="/_local_image_${encodeURIComponent(src)}" alt="${alt}" ${resAttrs} />`
+}
+
+export default function localImage (md) {
+  md.renderer.rules.image = resolveImage
+  md.renderer.rules.html_block = resolveHtmlImage
+  md.renderer.rules.html_inline = resolveHtmlImage
+}