fix(generator): add comments to src/index.js template

src/app/__snapshots__/index.test.js.snap

@@ -167,8 +167,11 @@ Object {
 `;
 
 exports[`generator:app src/ generates source file based on plugin name 1`] = `
-"export default function funTime() {
-
+"/**
+ * Danger plugin that tells you to have a fun time
+ */
+export default function funTime() {
+  // TODO
 }
 "
 `;

src/app/index.js

@@ -161,6 +161,7 @@ export default class extends Generator {
     this.fs.copy(this.templatePath('babelrc'), this.destinationPath('.babelrc'))
 
     this.fs.copyTpl(this.templatePath('src/**'), this.destinationPath('src'), {
+      ...this.props,
       pluginFunctionName,
     })
 

src/app/templates/src/index

@@ -1,3 +1,6 @@
+/**
+ * <%= description %>
+ */
 export default function <%= pluginFunctionName %>() {
-
+  // TODO
 }