docs: add how to install

Author: kemokemo

README.md

@@ -1,6 +1,6 @@
 # imgdiff
 
-[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT) [![CircleCI](https://circleci.com/gh/kemokemo/imgdiff.svg?style=svg)](https://circleci.com/gh/kemokemo/imgdiff)
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT) [![test-and-build](https://github.com/kemokemo/imgdiff/actions/workflows/test-and-build.yml/badge.svg)](https://github.com/kemokemo/imgdiff/actions/workflows/test-and-build.yml)
 
 This tool compares old and new versions of image files and generates color-coded image in a diff format.
 
@@ -11,6 +11,26 @@ Thanks to the wonderful [@murooka](https://github.com/murooka)'s [go-diff-image]
 
 ## Install
 
+### Homebrew
+
+```sh
+brew install kemokemo/tap/imgdiff
+```
+
+### Scoop
+
+First, add my scoop-bucket.
+
+```sh
+scoop bucket add kemokemo-bucket https://github.com/kemokemo/scoop-bucket.git
+```
+
+Next, install this app by running the following.
+
+```sh
+scoop install imgdiff
+```
+
 ### Binary
 
 Get the latest version from [the release page](https://github.com/kemokemo/imgdiff/releases/latest), and download the archive file for your operating system/architecture. Unpack the archive, and put the binary somewhere in your `$PATH`.
@@ -23,6 +43,7 @@ Usage: imgdiff [<option>...] <old image> <new image>
   -h	display help
   -o string
     	output filename (default "diff.png")
+  -v	display version
 ```
 
 This tool supports the following image formats.
@@ -40,7 +61,7 @@ $ imgdiff -o=diff/screen.png v1/screen.png v2/screen.png
 
 ## License
 
-[MIT](https://github.com/kemokemo/imgdiff/blob/master/LICENSE)
+[MIT](https://github.com/kemokemo/imgdiff/blob/main/LICENSE)
 
 ## Author