feat(command-dev): support Docusaurus V2 (#1228)

src/detectors/docusaurus.js

@@ -1,16 +1,32 @@
 const { hasRequiredDeps, hasRequiredFiles, getYarnOrNPMCommand, scanScripts } = require('./utils/jsdetect')
 module.exports = function() {
   // REQUIRED FILES
-  if (!hasRequiredFiles(['package.json', 'siteConfig.js'])) return false
+  if (!hasRequiredFiles(['package.json'])) return false
+
+  const hasV1 = hasRequiredDeps(['docusaurus'])
+  const hasV2 = hasRequiredDeps(['@docusaurus/core'])
+
   // REQUIRED DEPS
-  if (!hasRequiredDeps(['docusaurus'])) return false
+  if (!hasV1 && !hasV2) return false
+
+  // REQUIRED CONFIG FILE
+  const hasConfigFile = hasV1 ? hasRequiredFiles(['siteConfig.js']) : hasRequiredFiles(['docusaurus.config.js'])
+
+  if (!hasConfigFile) return false
 
   /** everything below now assumes that we are within gatsby */
 
-  const possibleArgsArrs = scanScripts({
+  const v1Command = {
     preferredScriptsArr: ['start'],
     preferredCommand: 'docusaurus-start',
-  })
+  }
+
+  const v2Command = {
+    preferredScriptsArr: ['start'],
+    preferredCommand: 'docusaurus start',
+  }
+
+  const possibleArgsArrs = scanScripts(hasV1 ? v1Command : v2Command)
 
   return {
     framework: 'docusaurus',