gui CHANGE show schemas in YANG explorer

very simple view in textual YANG form
diff --git a/frontend/yang/yang.component.html b/frontend/yang/yang.component.html
index 7bd403c..a3a3543 100644
--- a/frontend/yang/yang.component.html
+++ b/frontend/yang/yang.component.html
@@ -1,10 +1,18 @@
-<div class="netopeer-content">
+<nav #subnav id="subnav">
+    <a *ngFor="let schema of schemasService.schemas" [class.active]="schema.key==activeSchema.key"
+        (click)="changeActiveSchema(schema.key)">{{schema.name}}@{{schema.revision}}
+        <img class="tab-icon tab-close tab-action-last" src="assets/netopeer/icons/close.svg"  alt="x" title="close"
+            onmouseover="this.src='assets/netopeer/icons/close_active.svg'"
+            onmouseout="this.src='assets/netopeer/icons/close.svg'" (click)="close(schema.key)"/>
+    </a><a (click)="addSchema()" onmouseout="getElementById('tabadd').style.filter='invert(100%)'" onmouseover="getElementById('tabadd').style.filter='invert(0%)'">
+        <img id="tabadd" class="tab-icon tab-add tab-action-last" src="assets/netopeer/icons/add.svg" alt="+" title="open schema"
+            onmouseover="this.src='assets/netopeer/icons/add_active.svg'"
+            onmouseout="this.src='assets/netopeer/icons/add.svg'"/>
+    </a>
+</nav>
 
-    <p>YANG Explorer (TBD)</p>
-    <p>YANG schema browser</p>
-    <ul>
-        <li>navigate through the schemas (go to type definition, leafref target, etc)</li>
-    </ul>
+<div class="netopeer-content" [style.padding-top]="'calc(' + subnav.offsetHeight + 'px - -0.7em)'">
 
+    <pre *ngIf="activeSchema">{{activeSchema.data}}</pre>
 
 </div>
\ No newline at end of file