docs: add CONTRIBUTING.md (#962)

* docs: add CONTRIBUTING.md

* fix: CONTRIBUTING.md

Co-authored-by: Leonid Tyurin <lenyatyurin162586@gmail.com>

* docs: add commit message section

* docs: update pull request section

* docs: add chore description

---------

Co-authored-by: Leonid Tyurin <lenyatyurin162586@gmail.com>

Author: sevenzing

CONTRIBUTING.md

@@ -1,4 +1,81 @@
 Contributing to Blockscout-rs
 ===
 
-// todo
+First off, thanks for taking the time to contribute to 🚀 Blockscout-Rust 🚀 projects! 🎉
+
+## How Can I Contribute?
+
+The following is a set of guidelines for contributing to `blockscout-rs`, which is hosted in the Blockscout organization.
+
+### Reporting Bugs
+
+This section guides you through submitting a bug report. Following these guidelines helps maintainers and the community understand your report, reproduce the behavior, and find related reports.
+
+#### Before Submitting a Bug Report
+
+* Check the issues list to see if the problem has already been reported.
+* Update to the latest version and see if the issue persists.
+
+
+#### How Do I Submit a ✨Good✨ Bug Report?
+
+Bugs are tracked as GitHub issues. Create an issue and provide the following information by filling in the provided template:
+
+* Use a clear and descriptive title for the issue to identify the problem.
+* Describe the exact steps which reproduce the problem in as many details as possible.
+* Describe the behavior you observed after following the steps and explain why it is problematic.
+* Explain which behavior you expected to see instead and why.
+* Include screenshots, logs, ENVs, or any other information that might help in understanding the problem.
+* Mark the issue with the appropriate label (bug, enhancement, documentation, question, etc).
+
+### Contributing Code
+
+If you want to help us improve the project, you can contribute code. To do so, follow these steps:
+
+* Fork (https://github.com/blockscout/blockscout-rs/fork) the repository and make changes on your fork in a feature branch.
+* Create your branch with the name `<name>/<short-slug-of-your-feature-or-fix>`
+* Write code to implement features or fix bugs. Make sure your code is well-tested
+* Commit your changes. Commit messages **SHOULD** follow our [commit message conventions](#commit-messages-guidelines) format.
+* Create a pull request. The title of the pull request **MUST** follow the [commit message conventions](#commit-messages-guidelines) format.
+
+
+### Commit Messages Guidelines
+
+1. Use Conventional Commits:
+   * Follow [Conventional Commits v1.0.0](https://www.conventionalcommits.org/en/v1.0.0/).
+
+2. **Commit Types:**
+   > **Note:** those types are preferred, but you can use any other type if it fits better.
+
+   * `feat`: New feature
+   * `fix`: Bug fix
+   * `perf`: Performance improvement
+   * `chore`: Maintenance tasks (including code changes that do not fit other types)
+   * `refactor`: Code restructuring
+   * `ci`: Continuous Integration changes
+   * `docs`: Documentation updates
+   * `build`: Build system changes
+   * `config`: Configuration changes
+   * `test`: Adding or updating tests
+   * `revert`: Reverting commit changes
+
+3. Message Format `type(scope): description`
+   * **Type:** Lowercase (e.g., `feat`, `fix`)
+   * **Scope:** Service name (optional)
+   * **Description:** Short and concise (imperative mood)
+
+4. **Examples:**
+   * `feat: add new feature ...`
+   * `fix: correct bug ...`
+   * `docs: update README`
+   * `ci: add new workflow`
+
+5. Pull Request Titles
+
+   * **SHOULD** include service name (in `lower-kebab-case`) or other scope of change after `<type>`
+   * Examples:
+     * `feat(stats): add resolution for newAccounts chart`
+     * `fix(stats): correct wrong update bug`
+     * `docs: add CONTRIBUTING.md`
+     * `ci(verifier): update docker build step`
+