enhanced readme. fixes #11

Signed-off-by: Christian Dietrich <[email protected]>

demo/a.mydsl

@@ -1,4 +1,4 @@
-Hello A!
-Hello B from A!
-Hello name
- from Other!
+Hello Xtext!
+Hello VSCode from Xtext!
+Hello ThisFile from Other!
+Hello you!

demo/b.mydsl

@@ -1 +1,2 @@
+/* this is a definition in another file */
 Hello Other!

vscode-extension-self-contained/README.md

@@ -1,3 +1,40 @@
 # Xtext VS Code example
 
-This is a simple example showing the Xtext integration for VS Code based on the Microsoft Language Server Protocol. It allows you to edit `*.mydsl` files inside an opened folder.
+This is a simple example showing the [Xtext](https://www.eclipse.org/Xtext/) integration for VS Code based on the Microsoft [Language Server Protocol](https://github.com/Microsoft/language-server-protocol).
+
+The base is following simple grammar
+
+```
+Model:
+    greetings+=Greeting*;
+    
+Greeting:
+    'Hello' name=ID ('from' from=[Greeting])? '!';
+```
+
+A typical example model would look like (Open a new folder in VSCode and create the files)
+
+a.mydsl
+```
+Hello Xtext!
+Hello VSCode from Xtext!
+Hello ThisFile from Other!
+Hello you!
+```
+
+b.mydsl
+```
+/* this is a definition in another file */
+Hello Other!
+```
+
+The Xtext integration supports typical Xtext and Language Server features like
+
+* Syntax Highlighting
+* Validation
+* Cross References
+* Tooltips
+* Formatter
+* Mark Occurrences
+
+A introductory article can be found [here](https://blogs.itemis.com/en/integrating-xtext-language-support-in-visual-studio-code)