docs: update late install instructions

packages/@vue/cli-plugin-babel/README.md

@@ -29,8 +29,7 @@ module.exports = {
 ## Installing in an Already Created Project
 
 ``` sh
-npm install -D @vue/cli-plugin-babel
-vue invoke babel
+vue add @vue/babel
 ```
 
 ## Injected webpack-chain Rules

packages/@vue/cli-plugin-e2e-cypress/README.md

@@ -34,5 +34,5 @@ We've pre-configured Cypress to place most of the e2e testing related files unde
 ## Installing in an Already Created Project
 
 ``` sh
-vue add e2e-cypress
+vue add @vue/e2e-cypress
 ```

packages/@vue/cli-plugin-eslint/README.md

@@ -34,8 +34,7 @@ module.exports = {
 ## Installing in an Already Created Project
 
 ``` sh
-npm install -D @vue/cli-plugin-eslint
-vue invoke eslint
+vue add @vue/eslint
 ```
 
 ## Injected webpack-chain Rules

packages/@vue/cli-plugin-pwa/README.md

@@ -80,8 +80,7 @@ module.exports = {
 ## Installing in an Already Created Project
 
 ``` sh
-npm install -D @vue/cli-plugin-pwa
-vue invoke pwa
+vue add @vue/pwa
 ```
 
 ## Injected webpack-chain Rules

packages/@vue/cli-plugin-typescript/README.md

@@ -25,8 +25,7 @@ If opted to use [TSLint](https://palantir.github.io/tslint/) during project crea
 ## Installing in an Already Created Project
 
 ``` sh
-npm install -D @vue/cli-plugin-typescript
-vue invoke typescript
+vue add @vue/typescript
 ```
 
 ## Injected webpack-chain Rules