prettier file missing

everyone uses prettier code formatter , so everyone has different global prettier configuration, which leads to multiple unnecessary changes in file. So having a local `prettierrc` and `prettierignore` can eliminate these unnecessary changes.

Inspect the repository root and existing JavaScript project files to confirm where shared formatting configuration belongs. Add the requested local .prettierrc and .prettierignore files, then verify that the configuration is present and covers the files the project generates or maintains.

Written by the indexing model from the issue text.