Improve setup instructions for Apollo Boost.

Author: jaydenseric

changelog.md

@@ -9,6 +9,7 @@
 - Simplified the `prepublishOnly` script.
 - Add tips for React Native gotchas, via [#135](https://github.com/jaydenseric/apollo-upload-client/pull/135).
 - Updated the package description to mention that the upload link is terminating and clarified in the setup instructions that there can only be 1 terminating Apollo Link, via [#147](https://github.com/jaydenseric/apollo-upload-client/pull/147).
+- Improve setup instructions for Apollo Boost.
 
 ## 10.0.0
 

readme.md

@@ -14,7 +14,7 @@ Install with [npm](https://npmjs.com):
 npm install apollo-upload-client
 ```
 
-If you use [Apollo Boost](https://npm.im/apollo-boost), [migrate to a manual Apollo Client setup](https://apollographql.com/docs/react/advanced/boost-migration).
+[Apollo Boost](https://npm.im/apollo-boost) doesn’t allow link customization; if you are using it [migrate to a manual Apollo Client setup](https://apollographql.com/docs/react/advanced/boost-migration).
 
 [Apollo Client](https://apollographql.com/docs/link#apollo-client) can only have 1 “terminating” [Apollo Link](https://apollographql.com/docs/link) that sends the GraphQL requests; if one such as [`apollo-link-http`](https://apollographql.com/docs/link/links/http) is already setup, remove it.