Update diagram guide for Docsy 0.6

Author: Tim Bannister

content/en/docs/contribute/style/diagram-guide.md

@@ -473,7 +473,7 @@ Figure 6. Pod Topology Spread Constraints.
 
 Code block:
 
-``` 
+```text
 graph TB
 subgraph "zoneB"
 n3(Node3)
@@ -528,7 +528,7 @@ Figure 7. Ingress
 
 Code block:
 
-```mermaid
+```text
 graph LR;
 client([client])-. Ingress-managed <br> load balancer .->ingress[Ingress];
 ingress-->|routing rule|service[Service];
@@ -556,7 +556,7 @@ K8s components to start a container.
 
 Code block:
 
-```
+```text
 %%{init:{"theme":"neutral"}}%%
 sequenceDiagram
 actor me
@@ -592,7 +592,7 @@ In the code for
 [figure 7](https://mermaid-js..io/mermaid-live-editor/edit/#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),
 you can see examples of both.
 
-```
+```text
 classDef k8s fill:#326ce5,stroke:#fff,stroke-width:4px,color:#fff; // defines style for the k8s class
 class ingress,service,pod1,pod2 k8s; // k8s class is applied to elements ingress, service, pod1 and pod2.
 ```