chore: improve docs on iterative builds while developing

[alharris-at]

Description of changes

Updates to CONTRIBUTING.md to improve docs on iterative builds while developing.

CDK / CloudFormation Parameters Changed

N/A

Issue #, if available

N/A

Description of how you validated changes

N/A

Checklist

• PR description included
• Relevant documentation is changed or added (and PR referenced)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Merging #1510 (9558c5e) into main (e7fa6c3) will increase coverage by 0.47%.
The diff coverage is 54.68%.

❗ Your organization is not using the GitHub App Integration. As a result you may experience degraded service beginning May 15th. Please install the Github App Integration for your organization. Read more.

@@            Coverage Diff             @@
##             main    #1510      +/-   ##
==========================================
+ Coverage   61.89%   62.36%   +0.47%     
==========================================
  Files         358      361       +3     
  Lines       21390    21515     +125     
  Branches     5086     5115      +29     
==========================================
+ Hits        13239    13418     +179     
+ Misses       7390     7348      -42     
+ Partials      761      749      -12     

Impacted Files	Coverage Δ
...fy-category-api/src/category-utils/context-util.ts	21.62% <ø> (ø)
...rmation/cdk-stack-builder/apigw-stack-transform.ts	11.49% <ø> (ø)
...ormation/service-walkthroughs/apigw-walkthrough.ts	8.84% <0.00%> (ø)
...udformation/utils/migrate-api-override-resource.ts	64.28% <ø> (ø)
...s/awscloudformation/utils/rds-secrets/ssmClient.ts	66.66% <ø> (ø)
...transformer/src/graphql-predictions-transformer.ts	97.80% <ø> (ø)
...aphql-transformer-core/src/utils/type-map-utils.ts	11.71% <0.00%> (-0.79%)	⬇️
...il-mock/src/CFNParser/resource-processors/index.ts	0.00% <ø> (ø)
packages/amplify-util-mock/src/storage/storage.ts	0.00% <0.00%> (ø)
...y-util-mock/src/utils/lambda/load-lambda-config.ts	0.00% <0.00%> (ø)
... and 47 more

... and 3 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more