Add ESlint and lint action

[pearmini]

#266

• Add ESlint to support lint comments with these two rules: spaced-comment, capitalized-comments
• Set up a GitHub Action to run on every pull request to automatically check formatting and linting.

[Copilot]

Pull Request Overview

This PR adds ESLint configuration and CI automation to enforce code linting standards. The changes introduce two specific ESLint rules for comment formatting (spaced-comment and capitalized-comments) and establish automated checking through GitHub Actions.

• Configures ESLint with comment formatting rules and Prettier integration
• Sets up automated linting checks via GitHub Actions on every pull request
• Updates package.json scripts to support linting and auto-fixing

Reviewed Changes

Copilot reviewed 4 out of 5 changed files in this pull request and generated 3 comments.

File	Description
package.json	Adds ESLint dependencies and updates npm scripts for linting
eslint.config.mjs	Creates ESLint configuration with comment rules and Prettier integration
.prettierrc	Establishes Prettier formatting configuration
.github/workflows/ci.yml	Sets up GitHub Actions workflow for automated linting on PRs

Comments suppressed due to low confidence (1)

eslint.config.mjs:2

• The import path "eslint/config" does not exist in ESLint. The defineConfig function is not available from this path. You can remove this import as it's not needed for the flat config format.

import { defineConfig } from "eslint/config";

[shiffman]

This looks great to me! The question is when we should merge? Should we before finishing #248 and #257 so that it can be applied to those PRs or wait until after?

[gohai]

Just slightly curious what the difference is in terms of feature-set between prettier and ESlint? (Do we need both?)

[gohai]

Sorry, I overlooked the issue, which largely answers my question. (Could we switch to ESlint entirely?)

[pearmini]

@gohai We can fully switch to ESLint, but this requires additional configuration. Starting from ESLint v9, the ESLint team deprecated formatting and stylistic rules from the core due to high maintenance costs. Although a set of formatting rules is still maintained by the community, it’s generally easier to use Prettier as an out-of-the-box formatter.

[gohai]

So you're saying: both tools do something the other lacks, and we're best advised to use them both in tandem - correct?

[pearmini]

Yes, we use Prettier for formatting the code (whitespace management ) and use ESlint to lint the code (comments specifically here).

[gohai]

Thanks for your explanation, @pearmini! This makes sense to me then.