Enhance documentation to specify import rules from data/resource.ts

[noahmatsuyoshi]

Environment information

System:
  OS: Windows 11 10.0.22631
  CPU: (32) x64 13th Gen Intel(R) Core(TM) i9-13950HX
  Memory: 16.11 GB / 31.71 GB
Binaries:
  Node: 20.10.0 - C:\Program Files\nodejs\node.EXE
  Yarn: undefined - undefined
  npm: 10.2.3 - C:\Program Files\nodejs\npm.CMD
  pnpm: undefined - undefined
NPM Packages:
  @aws-amplify/backend: 0.13.0-beta.15
  @aws-amplify/backend-cli: 0.12.0-beta.17
  aws-amplify: Not Found
  aws-cdk: 2.136.0
  aws-cdk-lib: 2.136.0
  typescript: 5.4.4
AWS environment variables:
  AWS_NODEJS_CONNECTION_REUSE_ENABLED = 1
  AWS_SDK_LOAD_CONFIG = 1
  AWS_STS_REGIONAL_ENDPOINTS = regional
No CDK environment variables

Description

Importing anything other than Schema from resource.ts causes an error when running "npm run dev" or "npm run build". I'm guessing this is by design, but I wanted to call it out since the documentation doesn't make it obvious that this is not allowed, and it therefore took some time for me to find the issue in my code.