fix image form not displaying when added as first item in markdown widget

src/components/MarkdownPlugins/image.js

@@ -8,8 +8,8 @@ const image = {
     alt: match[1],
   },
   toBlock: data => `![${ data.alt || '' }](${ data.image || '' })`,
-  toPreview: (data, getAsset) => <img src={getAsset(data.image || '')} alt={data.alt || ''} />,
-  pattern: /^!\[([^\]]+)]\(([^)]+)\)$/,
+  toPreview: (data, getAsset) => <img src={getAsset(data.image) || ''} alt={data.alt || ''} />,
+  pattern: /^!\[(.*)\]\((.*)\)$/,
   fields: [{
     label: 'Image',
     name: 'image',