use local fhir ig instead of gitlab hosted fhir ig

Author: schwzr

docs/src/dsf-development/v2/fhir-ig.md

@@ -3,8 +3,8 @@ title: FHIR Implementation Guide
 icon: code
 ---
 
-<a href="https://ig-43c966.pages.it.hs-heilbronn.de/" target="_blank">Open Fullscreen</a>
-<iframe class="content-viewer" src="https://ig-43c966.pages.it.hs-heilbronn.de/"/>
+<a href="/fhir/ImplementationGuide/dev.dsf/index.html" target="_blank">Open Fullscreen</a>
+<iframe class="content-viewer" src="/fhir/ImplementationGuide/dev.dsf/index.html"/>
 
 <style>
 .content-viewer {