fix: assets data may lost due to md loader cache (#1649)

Author: PeachScript

src/loaders/markdown/index.ts

@@ -148,6 +148,10 @@ export default function mdLoader(this: any, content: string) {
   const opts: IMdLoaderOptions = this.getOptions();
   const cb = this.async();
 
+  // disable cache for avoid onResolveDemos and onResolveAtomMeta not work
+  // and dumi already save cache by self, loader cache is unnecessary
+  this.cacheable(false);
+
   const cache = getCache('md-loader');
   // format: {path:mtime:loaderOpts}
   const baseCacheKey = [