docs(): update install commands

src/@ionic-native/plugins/alipay/index.ts

@@ -102,7 +102,7 @@ export interface AlipayOrder {
   pluginRef: 'Alipay.Base',
   repo: 'https://github.com/xueron/cordova-alipay-base',
   platforms: ['Android', 'iOS'],
-  install: 'ionic plugin add https://github.com/xueron/cordova-alipay-base --variable APP_ID=your_app_id'
+  install: 'ionic cordova plugin add https://github.com/xueron/cordova-alipay-base --variable APP_ID=your_app_id'
 })
 @Injectable()
 export class Alipay extends IonicNativePlugin {

src/@ionic-native/plugins/facebook/index.ts

@@ -43,7 +43,7 @@ export interface FacebookLoginResponse {
  * Then type in the following command in your Terminal, where APP_ID and APP_NAME are the values from the Facebook Developer portal.
  *
  * ```bash
- *  ionic plugin add cordova-plugin-facebook4 --save --variable APP_ID="123456789" --variable APP_NAME="myApplication"
+ *  ionic plugin add cordova-plugin-facebook4 --variable APP_ID="123456789" --variable APP_NAME="myApplication"
  * ```
  *
  * After, you'll need to add the native platforms you'll be using to your app in the Facebook Developer portal under your app's Settings:
@@ -114,7 +114,7 @@ export interface FacebookLoginResponse {
   plugin: 'cordova-plugin-facebook4',
   pluginRef: 'facebookConnectPlugin',
   repo: 'https://github.com/jeduan/cordova-plugin-facebook4',
-  install: 'ionic plugin add cordova-plugin-facebook4 --variable APP_ID="123456789" --variable APP_NAME="myApplication"',
+  install: 'ionic cordova plugin add cordova-plugin-facebook4 --variable APP_ID="123456789" --variable APP_NAME="myApplication"',
   installVariables: ['APP_ID', 'APP_NAME'],
   platforms: ['Android', 'iOS']
 })

src/@ionic-native/plugins/photo-library/index.ts

@@ -44,7 +44,7 @@ import { Injectable } from '@angular/core';
   plugin: 'cordova-plugin-photo-library',
   pluginRef: 'cordova.plugins.photoLibrary',
   repo: 'https://github.com/terikon/cordova-plugin-photo-library',
-  install: 'ionic plugin add cordova-plugin-photo-library --variable PHOTO_LIBRARY_USAGE_DESCRIPTION="To choose photos"',
+  install: 'ionic cordova plugin add cordova-plugin-photo-library --variable PHOTO_LIBRARY_USAGE_DESCRIPTION="To choose photos"',
   platforms: ['Android', 'Browser', 'iOS']
 })
 @Injectable()

src/@ionic-native/plugins/pinterest/index.ts

@@ -172,7 +172,7 @@ export interface PinterestPin {
   plugin: 'cordova-plugin-pinterest',
   pluginRef: 'cordova.plugins.Pinterest',
   repo: 'https://github.com/zyramedia/cordova-plugin-pinterest',
-  install: 'ionic plugin add cordova-plugin-pinterest --variable APP_ID=YOUR_APP_ID',
+  install: 'ionic cordova plugin add cordova-plugin-pinterest --variable APP_ID=YOUR_APP_ID',
   installVariables: ['APP_ID'],
   platforms: ['Android', 'iOS']
 })

src/@ionic-native/plugins/push/index.ts

@@ -264,7 +264,7 @@ export type PushEvent = 'registration' | 'error' | 'notification';
   plugin: 'phonegap-plugin-push',
   pluginRef: 'PushNotification',
   repo: 'https://github.com/phonegap/phonegap-plugin-push',
-  install: 'ionic plugin add phonegap-plugin-push --variable SENDER_ID=XXXXXXXXX',
+  install: 'ionic cordova plugin add phonegap-plugin-push --variable SENDER_ID=XXXXXXXXX',
   installVariables: ['SENDER_ID']
 })
 @Injectable()

src/@ionic-native/plugins/rollbar/index.ts

@@ -25,7 +25,7 @@ import { Plugin, Cordova, IonicNativePlugin } from '@ionic-native/core';
   pluginRef: 'cordova.plugins.Rollbar',
   repo: 'https://github.com/Resgrid/cordova-plugins-rollbar',
   platforms: ['Android', 'iOS'],
-  install: 'ionic plugin add resgrid-cordova-plugins-rollbar --variable ROLLBAR_ACCESS_TOKEN="YOUR_ROLLBAR_ACCEESS_TOKEN" --variable ROLLBAR_ENVIRONMENT="ROLLBAR_ENVIRONMENT"',
+  install: 'ionic cordova plugin add resgrid-cordova-plugins-rollbar --variable ROLLBAR_ACCESS_TOKEN="YOUR_ROLLBAR_ACCEESS_TOKEN" --variable ROLLBAR_ENVIRONMENT="ROLLBAR_ENVIRONMENT"',
   installVariables: ['ROLLBAR_ACCESS_TOKEN', 'ROLLBAR_ENVIRONMENT']
 })
 @Injectable()

src/@ionic-native/plugins/twitter-connect/index.ts

@@ -56,7 +56,7 @@ export interface TwitterConnectResponse {
   plugin: 'twitter-connect-plugin',
   pluginRef: 'TwitterConnect',
   repo: 'https://github.com/ManifestWebDesign/twitter-connect-plugin',
-  install: 'ionic plugin add twitter-connect-plugin --variable FABRIC_KEY=fabric_API_key',
+  install: 'ionic cordova plugin add twitter-connect-plugin --variable FABRIC_KEY=fabric_API_key',
   installVariables: ['FABRIC_KEY']
 })
 @Injectable()