message: Remove API level files from `usage.md`
  Summary: The files are now integrated into a generated module to simplify usage.
diff: @@ -10,14 +10,9 @@ invocation is:
  ```
  A more complete invocation with:
  * the default configuration setting [config/default.config](https://github.com/facebook/redex/blob/master/config/default.config)
  -* Android Framework API description files
  * access to the Android SDK tools
  ```
  [python3] redex.py -c default.config \
  - -S android_sdk_api_14_file=path/to/service/api-levels/framework_classes_api_14.txt \
  - -S android_sdk_api_15_file=path/to/service/api-levels/framework_classes_api_15.txt \
  - [...] \
  - -S android_sdk_api_29_file=path/to/service/api-levels/framework_classes_api_29.txt \
  --android-sdk-path path/to/android/sdk \
  path/to/your.apk -o path/to/output.apk
  ```
  