docs: fix image labels

docs/images/pipe.graphml

@@ -232,7 +232,7 @@
           <y:Geometry height="30.0" width="100.0" x="97.75" y="114.05435163102959"/>
           <y:Fill color="#FFCC00" transparent="false"/>
           <y:BorderStyle color="#000000" type="line" width="1.0"/>
-          <y:NodeLabel alignment="center" autoSizePolicy="content" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasBackgroundColor="false" hasLineColor="false" height="18.1328125" modelName="custom" textColor="#000000" visible="true" width="51.42578125" x="24.287109375" y="5.93359375">rack11b<y:LabelModel>
+          <y:NodeLabel alignment="center" autoSizePolicy="content" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasBackgroundColor="false" hasLineColor="false" height="18.1328125" modelName="custom" textColor="#000000" visible="true" width="50.01953125" x="24.990234375" y="5.93359375">rack11c<y:LabelModel>
               <y:SmartNodeLabelModel distance="4.0"/>
             </y:LabelModel>
             <y:ModelParameter>

docs/images/topogit.graphml

@@ -360,7 +360,7 @@
           <y:Geometry height="30.0" width="110.0" x="87.75" y="138.5"/>
           <y:Fill color="#FFCC00" transparent="false"/>
           <y:BorderStyle color="#000000" type="line" width="1.0"/>
-          <y:NodeLabel alignment="center" autoSizePolicy="content" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasBackgroundColor="false" hasLineColor="false" height="18.1328125" modelName="custom" textColor="#000000" visible="true" width="51.42578125" x="29.287109375" y="5.93359375">rack11b<y:LabelModel>
+          <y:NodeLabel alignment="center" autoSizePolicy="content" fontFamily="Dialog" fontSize="12" fontStyle="plain" hasBackgroundColor="false" hasLineColor="false" height="18.1328125" modelName="custom" textColor="#000000" visible="true" width="50.01953125" x="29.990234375" y="5.93359375">rack11c<y:LabelModel>
               <y:SmartNodeLabelModel distance="4.0"/>
             </y:LabelModel>
             <y:ModelParameter>