Add contribution guidelines

Author: atifaziz

CONTRIBUTING.md

@@ -0,0 +1,53 @@
+# Contribution Guidelines
+
+You can help by contributing new examples or improve on existing ones that
+demonstrate how to use the various MoreLINQ methods and extensions.
+
+All it takes to add an example is the following fenced-block in a Markdown
+document:
+
+    ```c# --destination-file ../code/Program.cs --region statements --project ../code/TryMoreLinq.csproj
+    // replace this comment with your example code
+    ```
+
+**You can develop an example as a single C# expression or as C# statements.**
+In the above example, `--region statements` assumes the example code is
+expressed as one or more C# statements:
+
+    ```c# --destination-file ../code/Program.cs --region statements --project ../code/TryMoreLinq.csproj
+    var xs = Enumerable.Range(1, 5);
+    foreach (var x in xs)
+        Console.WriteLine(x);
+    ```
+
+To show an example as a single C# expression, instead, change
+`--region statements` to `--region expression`. The benefit is that you do not
+need to worry about looping and displaying the result of the expression via
+`Console.WriteLine`. This will be done automatically when the example is run
+interactively through Try .NET. Following is an example using an expression:
+
+    ```c# --destination-file ../code/Program.cs --region expression --project ../code/TryMoreLinq.csproj
+    Enumerable.Range(1, 5)
+    ```
+
+Note that expressions _must not_ be terminated by a semi-colon (`;`), which is
+the standard syntax rule in C#.
+
+Keep examples:
+
+- simple
+- clear
+- short
+- meaningful
+- self-contained
+
+**Wrap paragraphs in Markdown documents such that no line exceeds 78
+characters in length.** See the "Wrap Your Text" section of [Markdown Style
+Guide] on [Miguel de Icaza's Blog][tirania] for the background behind this
+choice.
+
+That's it! Fork away and submit your pull request!
+
+
+[Markdown Style Guide]: https://tirania.org/blog/archive/2014/Sep-30.html
+[tirania]: https://tirania.org/blog/

README.md

@@ -6,6 +6,9 @@ run and tested interactively in a browser using [`dotnet try`
 
 See [Setup](setup.md) for requirements and installation instructions.
 
+See the [Contribution Guidelines](CONTRIBUTING.md) if you would like to help
+contribute new examples or improve existing ones.
+
 
 ## Examples