Fix for changes in @types/unist

Author: wooorm

lib/core.js

@@ -92,7 +92,7 @@ export function core(schema, defaultTagName, caseSensitive) {
           addChild(node.children, children[index])
         }
 
-        if (node.tagName === 'template') {
+        if (node.type === 'element' && node.tagName === 'template') {
           node.content = {type: 'root', children: node.children}
           node.children = []
         }
@@ -123,7 +123,7 @@ function isProperties(value, name) {
     return true
   }
 
-  if (Array.isArray(value.children)) {
+  if ('children' in value && Array.isArray(value.children)) {
     return false
   }