Update doc

Author: jcs090218

docs/page/langs/csharp.md

@@ -4,6 +4,18 @@ You can customize variable `docstr-csharp-style` for the following value.
 
 * `nil` - Respect to user's customization
 
+C# currently uses mix of [Javadoc](https://en.wikipedia.org/wiki/Javadoc) and
+[XML documentation](https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/xmldoc/)
+.
+
+## Triggerations
+
+Generally, you will need something around to parse to make document string work 
+correctly.
+
+* `/*[*]*/` - hit return between `/*` and `*/` (Javadoc)
+* `///` - the third slashes (XML documentation)
+
 ## References
 
-* N/A
+* [Documentation comments - C# langauge specification](https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/language-specification/documentation-comments)