Updating readme with vale instructions

README.md

@@ -91,6 +91,7 @@ For more details, please try [Getting started](./docs/en/getting-started.md).
 - Node.js environment 22.13.*
 - [`gcloud` CLI](https://cloud.google.com/sdk/docs/install)
 - [`jq` command](https://jqlang.org/)
+- [ `vale` command](https://github.com/errata-ai/vale)
 
 #### Initialization (one-time setup)
 1. Download or clone this repository   
@@ -99,6 +100,33 @@ For more details, please try [Getting started](./docs/en/getting-started.md).
   e.g. `cd khi`
 1. Run `cd ./web && npm install` from the project root
 
+#### Vale linting 
+We use Vale to enforce our documentation style and ensure consistency across our Markdown files.
+
+### Installation of Vale
+
+#### macOS
+    ```bash
+    brew install vale
+    ```
+
+#### Windows
+    ```bash
+    scoop install vale
+    ```
+
+#### Linux
+    ```bash
+    curl -L "https://github.com/errata-ai/vale/releases/download/v2.22.0/vale_2.22.0_Linux_64-bit.tar.gz" -o vale.tar.gz
+    tar -xzvf vale.tar.gz
+    sudo mv vale /usr/local/bin/vale
+    ```
+
+#### How to run Vale locally
+    ```bash
+    vale .
+    ```
+
 #### Run KHI
 1. [Authorize yourself with `gcloud`](https://cloud.google.com/docs/authentication/gcloud)  
   e.g. `gcloud auth login` if you use your user account credentials