docs: add README

Signed-off-by: Mateusz Urbanek <mateusz.urbanek.98@gmail.com>

README.md

@@ -0,0 +1,90 @@
+# Labeler - Declarative GitHub Label Syncing CLI Tool
+
+[![GitHub Release](https://img.shields.io/github/v/release/shanduur/labeler)](https://github.com/shanduur/labeler/releases/latest)
+[![GitHub License](https://img.shields.io/github/license/shanduur/labeler)](LICENSE)
+
+Labeler is a command-line interface (CLI) tool designed to facilitate the declarative synchronization of GitHub labels across repositories. This tool provides an efficient and convenient way to manage labels in a GitHub repository by enabling users to define label configurations in a YAML file and then apply or retrieve these configurations using the provided commands.
+
+## Table of Contents
+
+- [Labeler - Declarative GitHub Label Syncing CLI Tool](#labeler---declarative-github-label-syncing-cli-tool)
+  - [Table of Contents](#table-of-contents)
+  - [Usage](#usage)
+    - [Uploading Labels](#uploading-labels)
+    - [Downloading Labels](#downloading-labels)
+  - [Configuration File](#configuration-file)
+  - [Examples](#examples)
+  - [License](#license)
+  - [Changelog](#changelog)
+
+## Usage
+
+### Uploading Labels
+
+To sync labels from a file to a GitHub repository, use the following command:
+
+```bash
+labeler upload [options] <path-to-labels-file>
+```
+
+Example:
+
+```bash
+labeler upload --repository <owner>/<repo> examples/cli/labels.yaml
+```
+
+### Downloading Labels
+
+To download and print GitHub repository labels to a file, use the following command:
+
+```bash
+labeler download [options] <path-to-output-file>
+```
+
+Example:
+
+```bash
+labeler download --repository <owner>/<repo> examples/cli/labels.yaml
+```
+
+**Note:** Replace `<owner>/<repo>` with the GitHub owner and repository name you intend to work with.
+
+## Configuration File
+
+The configuration file for Labeler is a YAML file that defines the labels and their attributes to be synchronized with a GitHub repository. Below is an example of a label configuration file:
+
+```yaml
+- name: dependency
+  color: '#dadada'
+  description: Dependency updates
+- name: feature-request
+  color: '#61dafb'
+  description: Request for a new feature or enhancement
+- name: documentation
+  color: '#007bc7'
+  description: Issues related to documentation
+- name: bug
+  color: '#d73a4a'
+  description: Something isn't working as expected
+```
+
+In this example, each label is defined with the following attributes:
+- **name:** The name of the label.
+- **color:** The color associated with the label, specified in hexadecimal format.
+- **description:** A brief description of the label's purpose or meaning.
+
+Ensure that the configuration file adheres to the YAML syntax, and you can customize it according to your project's specific label requirements.
+
+## Examples
+
+Example label configurations are provided in the `examples` directory for different scenarios, including CLI, Kubernetes, and Moby projects.
+
+## License
+
+Labeler is licensed under the [MIT License](LICENSE).
+
+## Changelog
+
+Check out the [Changelog](CHANGELOG.md) to see the release history and updates.
+
+For detailed information on commands and options, run `labeler help`.

cmd/labeler/download/download.go

@@ -28,6 +28,7 @@ var (
 func New() *cli.Command {
 	return &cli.Command{
 		Name:    "download",
+		Usage:   "Download and print GitHub repository labels to a file",
 		Aliases: []string{"d", "dl"},
 		Flags: []cli.Flag{
 			flagOutput,

cmd/labeler/main.go

@@ -11,6 +11,7 @@ import (
 )
 
 var app = &cli.Command{
+	Usage: "Declarative GitHub label syncing tool",
 	Commands: []*cli.Command{
 		upload.New(),
 		download.New(),

cmd/labeler/upload/upload.go

@@ -34,6 +34,7 @@ var (
 func New() *cli.Command {
 	return &cli.Command{
 		Name:      "upload",
+		Usage:     "Sync labels from a file to a GitHub repository",
 		Aliases:   []string{"u", "up"},
 		ArgsUsage: "<file>",
 		Flags: []cli.Flag{

go.mod

@@ -1,6 +1,6 @@
 module github.com/shanduur/labeler
 
-go 1.20
+go 1.21
 
 require (
 	github.com/google/go-github/v53 v53.2.0