[core] Clarify transform-runtime, runtime version

Author: eps1lon

babel.config.js

@@ -44,7 +44,8 @@ module.exports = {
     'babel-plugin-optimize-clsx',
     ['@babel/plugin-proposal-class-properties', { loose: true }],
     ['@babel/plugin-proposal-object-rest-spread', { loose: true }],
-    '@babel/plugin-transform-runtime',
+    // any package needs to declare 7.4.4 as a runtime dependency. default is ^7.0.0
+    ['@babel/plugin-transform-runtime', { version: '^7.4.4' }],
     // for IE 11 support
     '@babel/plugin-transform-object-assign',
   ],

docs/babel.config.js

@@ -23,7 +23,11 @@ const alias = {
 };
 
 module.exports = {
-  presets: ['next/babel', '@zeit/next-typescript/babel'],
+  presets: [
+    // we can use the version that is referenced in the lockfile
+    ['next/babel', { 'transform-runtime': { version: '^7.7.4' } }],
+    '@zeit/next-typescript/babel',
+  ],
   plugins: [
     'babel-plugin-optimize-clsx',
     // for IE 11 support