docs: add CONTRIBUTORS and MAINTAINERS files, update README (#18)

* docs: README update

* docs: introduce CONTRIBUTING.md

* docs: introduce MAINTAINERS.txt

CONTRIBUTING.md

@@ -0,0 +1,78 @@
+
+# Contributing Guide
+
+You can contribute to `pmg` and help make it better. Apart from bug fixes,
+features, we particularly value contributions in the form of:
+
+- Documentation improvements
+- Bug reports
+- Using `pmg` in your projects and providing feedback
+
+## How to contribute
+
+1. Fork the repository
+2. Add your changes
+3. Submit a pull request
+
+## How to report a bug
+
+Create a new issue and add the label "bug".
+
+## How to suggest a new feature
+
+Create a new issue and add the label "enhancement".
+
+## Development workflow
+
+When contributing changes to repository, follow these steps:
+
+1. Ensure tests are passing
+2. Ensure you write test cases for new code
+3. `Signed-off-by` line is required in commit message (use `-s` flag while committing)
+
+## Developer Setup
+
+### Requirements
+
+- Go 1.24+
+- Git
+- Make
+
+### Getting Started
+
+1. Clone your fork:
+   ```bash
+   git clone https://github.com/YOUR_USERNAME/pmg.git
+   cd pmg
+   ```
+
+2. Install dependencies:
+   ```bash
+   go mod tidy
+   ```
+
+3. Build the project:
+   ```bash
+   make all
+   ```
+
+### Development Workflow
+
+1. Create a branch:
+   ```bash
+   git checkout -b feature/your-feature
+   ```
+
+2. Make your changes and test:
+   ```bash
+   make test
+   ```
+
+3. Commit with sign-off:
+   ```bash
+   git commit -s -m "feat: add new feature"
+   ```
+
+4. Push and create PR:
+   ```bash
+   git push origin feature/your-feature