Create Public Samples root directory. (microsoftgraph#300)

* Create Public Samples root directory.

* Update and rename README.md to Sample_README_Template.md

* Update Sample_README_Template.md

* Update Sample_README_Template.md

Addressed comments.

Samples/PublicSamples/Sample_README_Template.md

@@ -0,0 +1,28 @@
+Please use content below as template in your Sample's READM.md file.
+====================================================================
+
+> **Note:**  
+> Public Samples are provided by developers from the Microsoft Graph community.  
+> Public Samples are not official Microsoft Communication samples, and not supported by the Microsoft Communication engineering team. It is recommended that you contact the sample owner before using code from Public Samples in production systems.
+
+---
+Title: "Your Sample Name in PascalCase"  
+Description: "Short description of this sample."  
+author: "Github username of the author, for contact"  
+---
+
+# Introduction
+
+## Getting Started (required)
+
+This section walks you through the process of deploying and testing the sample bot.
+
+### Bot Registration (required)
+
+### Prerequisites (required)
+
+### Deploy (One of Deploy and Local Run is required)
+
+### Local Run (One of Deploy and Local Run is required)
+
+### Test (required)