Add configuration for ClientAwareness to Doc

[saboyutaka]

Since apollo-client v2.4.7, client name and version for ClientAwareness added to ApolloClient. And Apollo Studio is Segmente metrics by this. I think additing how to set these options would be more helpful.

https://github.com/Akryum/vue-cli-plugin-apollo/blob/master/docs/guide/configuration.md

createApolloClient({
  // URL to the HTTP API
  httpEndpoint,
  // Url to the Websocket API
  wsEndpoint: null,
  // Token used in localstorage
  tokenName: 'apollo-token',
  // Enable this if you use Query persisting with Apollo Engine
  persisting: false,
  // Or, advanced persisting options, see https://github.com/apollographql/apollo-link-persisted-queries#options
  // Example:
  // persisting: {
  //  generateHash: query => sha256()
  //    .update(print(query))
  //    .digest('hex'),
  //},
  // Is currently Server-Side Rendering or not
  ssr: false,
  // Only use Websocket for all requests (including queries and mutations)
  websocketsOnly: false,
  // Custom starting link.
  // If you want to replace the default HttpLink, set `defaultHttpLink` to false
  link: null,
  // Custom pre-auth links
  // Useful if you want, for example, to set a custom middleware for refreshing an access token.
  preAuthLinks: [],
  // If true, add the default HttpLink.
  // Disable it if you want to replace it with a terminating link using `link` option.
  defaultHttpLink: true,
  // Options for the default HttpLink
  httpLinkOptions: {},
  // Custom Apollo cache implementation (default is apollo-cache-inmemory)
  cache: null,
  // Options for the default cache
  inMemoryCacheOptions: {},
  // Additional Apollo client options
- apollo: {},
+ apollo: {
+   name: 'client-name',
+   version: 'x.x'
+ },
  // apollo-link-state options
  clientState: null,
  // Function returning Authorization header token
  getAuth: defaultGetAuth,
})