feat(coverage): include json reporter by default

Author: antfu

packages/vitest/src/defaults.ts

@@ -26,7 +26,7 @@ const coverageConfigDefaults = {
  reportsDirectory: './coverage',
  excludeNodeModules: true,
  exclude: defaultCoverageExcludes,
- reporter: ['text', 'html', 'clover'],
+ reporter: ['text', 'html', 'clover', 'json'],
  allowExternal: false,
  // default extensions used by c8, plus '.vue' and '.svelte'
  // see https://github.com/istanbuljs/schema/blob/master/default-extension.js