adding link to markdown format to our Readme

README.md

@@ -12,4 +12,4 @@ Welcome to the DH Class Hub! This is a repository to help introduce and orient P
 
 * **Always be sure to "sync"** your local folder to receive any changes pushed to this GitHub repository. At command line, that means, issue a **"git pull"** (or a **"git fetch"** and **"git merge"**) command to retrieve changes to the directories from the cloud before you begin working. Always sync your local directory with our cloud directory here on the web **when you begin work**, and **when you conclude work** at a local computer.
 
-* There are things we'll do together **only in the webpage view of GitHub:** See if you can find the "Issues" and "Wiki" areas by mousing over the icons on the top (in the new view) or the right-hand (old view) side of the GitHub page: "Issues" is the exclamation point inside the circle, and the "Wiki" pages will be under the icon for a book. We're using the "Issues" page to open conversations about questions, problems, things we need to discuss and fix and work on together. If we formulate a new method or policy we definitely want to follow, we'll post a Wiki page about it. The Issues and Wikis are searchable, and you write in them using "markdown," which lets you easily and quickly format headings, lists, bold, italics, or share an image, etc. 
+* There are things we'll do together **only in the webpage view of GitHub:** See if you can find the "Issues" and "Wiki" areas by mousing over the icons on the top (in the new view) or the right-hand (old view) side of the GitHub page: "Issues" is the exclamation point inside the circle, and the "Wiki" pages will be under the icon for a book. We're using the "Issues" page to open conversations about questions, problems, things we need to discuss and fix and work on together. If we formulate a new method or policy we definitely want to follow, we'll post a Wiki page about it. The Issues and Wikis are searchable, and you write in them using [markdown syntax](https://guides.github.com/features/mastering-markdown/), which lets you easily and quickly format headings, lists, bold, italics, or share an image, etc.