style(editorconfig): improve markdown and json indentation consistency

[Fel65]

Added consistent indentation rules for Markdown and JSON files to align with Prettier and ESLint formatting standards.
This ensures unified code style and improves readability for contributors.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1

[vercel]

@Fel65 is attempting to deploy a commit to the Coinbase Team on Vercel.

A member of the Team first needs to authorize it.

[Fel65]

Thanks for maintaining this project 🙌
While reviewing the .editorconfig, I noticed that Markdown and JSON formatting rules were missing, which could lead to inconsistent indentation across contributors.
This small improvement aligns with Prettier and ESLint defaults and helps keep the codebase style unified.