Update stage-documentation-changes.md (#5213)

* Update stage-documentation-changes.md

Fix the format. The format in orginal web page is confusion.

* convert note to callout

* make note multiline

* fix code block

docs/home/contribute/stage-documentation-changes.md

@@ -74,13 +74,8 @@ web server:
 
 1. View your staged content at `http://localhost:4000`.
 
-<i>NOTE: If you do not want Jekyll to interfere with your other globally installed gems, you can use `bundler`:</i> 
+**Note:** "If you do not want Jekyll to interfere with your other globally installed gems, you can use `bundler`: <br /> <br /> ```gem install bundler``` <br /> ```bundle install``` <br /> ```bundler exec jekyll serve``` <br /> <br /> Regardless of whether you use `bundler` or not, your copy of the site will then be viewable at: http://localhost:4000
- 
+{: .note}
- 	gem install bundler
- 	bundle install
- 	bundler exec jekyll serve
-
-<i> Regardless of whether you use `bundler` or not, your copy of the site will then be viewable at: http://localhost:4000</i>
 
 {% endcapture %}