Corrected case in links

Fixes #3

Author: jasonjoh

README.md

@@ -10,17 +10,17 @@ In this lab you will create a React single-page application, configured with Azu
 
 ## Demos
 
-The [Demos](./Demos) directory in this repository contains copies of the project that correspond to completing individual sections of the tutorial. If you just want to demo a particular section of the tutorial, you can start with the version from the previous section.
+The [demos](./demos) directory in this repository contains copies of the project that correspond to completing individual sections of the tutorial. If you just want to demo a particular section of the tutorial, you can start with the version from the previous section.
 
-- [01-create-app](Demos/01-create-app): Completed [Create a React single-page app](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=1)
-- [02-add-aad-auth](Demos/02-add-aad-auth): Completed [Add Azure AD authentication](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=3)
-- [03-add-msgraph](Demos/03-add-msgraph): Completed [Get calendar data](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=4)
+- [01-create-app](demos/01-create-app): Completed [Create a React single-page app](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=1)
+- [02-add-aad-auth](demos/02-add-aad-auth): Completed [Add Azure AD authentication](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=3)
+- [03-add-msgraph](demos/03-add-msgraph): Completed [Get calendar data](https://docs.microsoft.com/graph/training/react-tutorial?tutorial-step=4)
 
 ## Completed sample
 
 If you just want the completed sample generated by following this lab, you can find it here.
 
-- [Completed project](Demos/03-add-msgraph)
+- [Completed project](demos/03-add-msgraph)
 
 ## Disclaimer