Include CNAME file (#83)

* update README.md file

* Update README.md with CNAME doc link

Author: viniciuspereiras

README.md

@@ -69,6 +69,9 @@ tag_permalink_style: pretty
 tag_page_layout: tag_page
 tag_page_dir: tag
 
+# for github pages custom domains:
+# include: [CNAME]
+
 dash:
   # the way how dates should be displayed
   date_format: "%b %-d, %Y"
@@ -115,6 +118,12 @@ I have created [a guide on how to set this up here](https://bitbra.in/2021/10/03
 
 You are not required to do this, but keep in mind that some functionality might not be available when using the Jekyll generator on Github directly!
 
+If you are using a custom domain add in your main branch a file named CNAME with your domain there and uncomment this line in your config file:
+```
+include: [CNAME]
+```
+For more information about how to configure your CNAME file, read the [official documentation](https://docs.github.com/en/pages/configuring-a-custom-domain-for-your-github-pages-site/managing-a-custom-domain-for-your-github-pages-site).
+
 ## Additional Features
 
 **Tagging** add the `jekyll/tagging` plugin to your `_config.yml` file to enable tagging. Do not forget to also add the following to your `Gemfile`: