Add spring-boot to spring-projects.js

Author: rwinch

src/helpers/spring-projects.js

@@ -1,6 +1,11 @@
 'use strict'
 
 module.exports = () => [
+  {
+    href: 'https://docs.spring.io/spring-boot/',
+    id: 'boot',
+    text: 'Spring Boot',
+  },
   {
     href: 'https://docs.spring.io/spring-framework/reference/',
     id: 'framework',