Refine how TypeScript env types are handled (#5593)

* Specify types in package

* Do not remove types file on eject

* Stop copying types into generated project

* Reference react and react-dom

* Reference node types

* Install node types as well

* Restore copying

* Add Node to the list of installed types

* Reference Jest types

* Remove jest types from install

* Remove jest from CRA install

* Remove Jest reference and let user do this themselves

* Stop copying types file

* Add types key to package.json

* Add appTypeDeclarations and create when missing

* Rename declarations file

* Add Jest back to install instructions

* Minimize diff

packages/react-scripts/config/paths.js

@@ -84,6 +84,7 @@ module.exports = {
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
+  appTypeDeclarations: resolveApp('src/react-app-env.d.ts'),
   yarnLockFile: resolveApp('yarn.lock'),
   testsSetup: resolveModule(resolveApp, 'src/setupTests'),
   proxySetup: resolveApp('src/setupProxy.js'),
@@ -106,6 +107,7 @@ module.exports = {
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
+  appTypeDeclarations: resolveApp('src/react-app-env.d.ts'),
   yarnLockFile: resolveApp('yarn.lock'),
   testsSetup: resolveModule(resolveApp, 'src/setupTests'),
   proxySetup: resolveApp('src/setupProxy.js'),
@@ -138,6 +140,7 @@ if (
     appPackageJson: resolveOwn('package.json'),
     appSrc: resolveOwn('template/src'),
     appTsConfig: resolveOwn('template/tsconfig.json'),
+    appTypeDeclarations: resolveOwn('template/src/react-app-env.d.ts'),
     yarnLockFile: resolveOwn('template/yarn.lock'),
     testsSetup: resolveModule(resolveOwn, 'template/src/setupTests'),
     proxySetup: resolveOwn('template/src/setupProxy.js'),