add building the site section in readme

README.md

@@ -24,6 +24,18 @@ mkdocs serve
 
 This will start a local server at `http://localhost:8000/` where you can preview the documentation.
 
+## Building the Site
+
+For deploying the docs on [GitHub Pages](https://pages.github.com/) mkdocs has the `mkdocs gh-deploy` command which is used in [docs workflow](https://github.com/sourcefuse/arc-docs/blob/main/.github/workflows/docs.yaml).
+
+However, If you want to build the site locally, you can do so by running the following command:
+
+```sh
+mkdocs build
+```
+
+This will create the folder named `site` containing the static build files. Similar to what arc-docs have in its [`gh-pages`](https://github.com/sourcefuse/arc-docs/tree/gh-pages) branch.
+
 ## Navigation
 
 We use the `mkdocs-awesome-pages-plugin` to organize our documentation as it provides more features than default mkdocs nav options. To configure navigation for a particular section, please create/modify the `.pages.yml` file in that folder and add the appropriate navigation links.