build: add README for server examples

Author: bk138

examples/server/README.md

@@ -0,0 +1,7 @@
+This directory contains simple examples showcasing certain parts of LibVNCServer's functionality.
+
+Some more full-blown implementations are:
+
+* [x11vnc](https://github.com/LibVNC/x11vnc) for X11
+* [droidVNC-NG](https://github.com/bk138/droidVNC-NG) for Android
+* [macVNC](https://github.com/LibVNC/macVNC) for macOS