docs: update document

README.md

@@ -1,16 +1,38 @@
 [![Test](https://github.com/KEINOS/gh-action-hash-for-cache/actions/workflows/basic_func_test.yml/badge.svg)](https://github.com/KEINOS/gh-action-hash-for-cache/actions/workflows/basic_func_test.yml)
 [![linux-mac-win](https://github.com/KEINOS/gh-action-hash-for-cache/actions/workflows/platform_test.yml/badge.svg)](https://github.com/KEINOS/gh-action-hash-for-cache/actions/workflows/platform_test.yml)
 
-# GitHub Actions to Generate Hash for Caching on Linux, macOS, and Windows runners
+# Unique Key (file hash) Generator for Caching
+
+This GitHub Action generates a unique key (file hash) from one or more files for caching. It works on Linux, macOS, and Windows runners.
+
+```yaml
+- name: <name of the step to display>
+  uses: KEINOS/gh-action-hash-for-cache@main
+  id: <ID to call the hash from other steps>
+  with:
+    path: |
+      <path to target file1>
+      <path to target file2>
+    variant: <a string>
+```
+
+- `path`: A list of files that will be hashed.
+- `variant`: A string to be hashed. (Optional)
+- Exposed variable: `hash`
+  - To obtain the hash value: `steps.<id>.outputs.hash`
+
+## About
 
 [This GitHub Action](https://github.com/KEINOS/gh-action-hash-for-cache):
 
 - **Simply generates a hash of the given entry**.
   - If the content of the entry is changed, a different hash will be obtained.
-  - Useful to generate a key or ID for caching.
+  - Useful to generate a unique key or ID for caching.
 - Works on Linux, macOS, and Windows runners.
 - Aims to be a helper action for "[actions/cache@v2](https://github.com/marketplace/actions/cache)".
-- It is also possible to specify a time-limited variant.
+- It is also possible to specify a time-limited hash.
+- Help us to fix [issues](https://github.com/KEINOS/gh-action-hash-for-cache/issues) @ GitHub.
+- View on [marketplace](https://github.com/marketplace/actions/file-hash-for-cache).
 
 ## Usage
 
@@ -39,11 +61,29 @@ jobs:
 
 - Exposed variables: `steps.<id>.outputs.hash`
 
-## Example
+## Examples
 
 ### On File Change
 
-In this example, if "composer.json" or "composer.lock" is changed, the hash will be changed.
+In this example, if "Dockerfile" is changed, the hash will be changed.
+
+```yaml
+- name: Get a hash key from two files
+  id: hash-now-dont-you-cry
+  uses: KEINOS/gh-action-hash-for-cache@main
+  with:
+    path: |
+      ./Dockerfile
+
+- name: Activate caching
+  id: cache
+  uses: actions/cache@v2
+  with:
+    path: /path/target/dir/to/cache/and/restore
+    key: ${{ steps.hash-now-dont-you-cry.outputs.hash }}
+```
+
+Multiple target files can be specified. The below example, if "composer.json" or "composer.lock" is changed, the hash will be changed.
 
 ```yaml
 - name: Get a hash key from two files

action.yml

@@ -1,5 +1,5 @@
-name: "File Hash for cache"
-description: 'Generates a hash of the given entry for cache key.'
+name: "File Hash for Cache"
+description: 'Generates a unique key (hash) from one or more files for caching.'
 author: 'KEINOS'
 
 branding: