chore: add GitHub pull request template

[dicethedev]

Summary

This PR adds a repository-level pull request template so future contributions follow a clear and consistent structure. It should reduce inconsistent PR descriptions, improve review quality, and make it easier to spot missing context up front.

---

Added PULL_REQUEST_TEMPLATE.md to provide a consistent PR structure for ethlambda.

Changes

• Standardizes how contributors describe changes and motivations
• Includes explicit sections for:
  • Description / Motivation
  • What Changed
  • Correctness / Behavior Guarantees
  • Tests Added / Run
  • Related Issues / PRs

Why this change?

• Helps reviewers quickly understand the scope, intended behavior, and verification steps
• Encourages contributors to document tests and issue links before opening a PR
• Reduces inconsistent or incomplete PR descriptions
• Improves overall review quality and project maintainability

Closes #320

[greptile-apps]

Greptile Summary

Adds .github/PULL_REQUEST_TEMPLATE.md to standardize PR descriptions across the project. The template covers motivation, changes, correctness guarantees, tests, and related issues — a clean, low-risk addition with one minor nit about the top-level heading.

Confidence Score: 5/5

Safe to merge — only a documentation/template file is added with no logic changes.

Single markdown file addition with no code changes. The only finding is a P2 style nit about the H1 heading rendering verbatim in PR descriptions.

No files require special attention.

Important Files Changed

Filename	Overview
.github/PULL_REQUEST_TEMPLATE.md	Adds a new PR template with sections for description, changes, correctness, tests, and related issues; the # Pull Request Template H1 heading will render verbatim in every contributor's PR description.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Contributor opens new PR] --> B[GitHub loads PULL_REQUEST_TEMPLATE.md]
    B --> C[Template pre-fills PR description box]
    C --> D{Contributor fills in sections}
    D --> E[Description / Motivation]
    D --> F[What Changed]
    D --> G[Correctness / Behavior Guarantees]
    D --> H[Tests Added / Run]
    D --> I[Related Issues / PRs]
    E & F & G & H & I --> J[PR submitted with structured description]
    J --> K[Reviewer gets consistent, complete context]

Loading

Prompt To Fix All With AI

This is a comment left during a code review.
Path: .github/PULL_REQUEST_TEMPLATE.md
Line: 1

Comment:
**H1 heading will appear verbatim in every PR description**

GitHub injects the template contents directly into the PR description text box, so the `# Pull Request Template` line will show up in every submitted PR until contributors manually delete it. Most teams omit this heading, or use an HTML comment (`<!-- ... -->`) so it stays invisible in the rendered description.

```suggestion
<!-- PR Template — fill in the sections below and delete any that don't apply -->
```

How can I resolve this? If you propose a fix, please make it concise.

_{Reviews (1): Last reviewed commit: "chore: add GitHub pull request template" | Re-trigger Greptile}

[MegaRedHand]

Congratulations on your first contribution to ethlambda! 🥳

[dicethedev]

Congratulations on your first contribution to ethlambda! 🥳

Thank you! More to fix, add and refactor. I'm here for all that!