feat: support audio src in transformAssetUrls option by default (#72)

fix issues like
vuejs/vue-cli#4792
and
nuxt/docs#1256

Author: haoqunjiang

README.md

@@ -77,6 +77,7 @@ interface TemplateCompileOptions {
   // Transform asset urls found in the template into `require()` calls
   // This is off by default. If set to true, the default value is
   // {
+  //   audio: 'src',
   //   video: ['src', 'poster'],
   //   source: 'src',
   //   img: 'src',

lib/templateCompilerModules/assetUrl.ts

@@ -7,6 +7,7 @@ export interface AssetURLOptions {
 }
 
 const defaultOptions: AssetURLOptions = {
+  audio: 'src',
   video: ['src', 'poster'],
   source: 'src',
   img: 'src',