mark yaml examples as such to get syntax highlighting

Author: dastrobu

content/en/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions.md

@@ -221,51 +221,51 @@ A structural schema is an [OpenAPI v3.0 validation schema](#validation) which:
 
 Non-structural example 1:
 
-```none
+```yaml
 allOf:
 - properties:
  foo:
- ...
+ # ...
 ```
 
 conflicts with rule 2. The following would be correct:
 
-```none
+```yaml
 properties:
  foo:
- ...
+ # ...
 allOf:
 - properties:
  foo:
- ...
+ # ...
 ```
 
 Non-structural example 2:
 
-```none
+```yaml
 allOf:
 - items:
  properties:
  foo:
- ...
+ # ...
 ```
 conflicts with rule 2. The following would be correct:
 
-```none
+```yaml
 items:
  properties:
  foo:
- ...
+ # ...
 allOf:
 - items:
  properties:
  foo:
- ...
+ # ...
 ```
 
 Non-structural example 3:
 
-```none
+```yaml
 properties:
  foo:
  pattern: "abc"
@@ -479,7 +479,7 @@ properties:
 Also those nodes are partially excluded from rule 3 in the sense that the following two patterns are allowed
 (exactly those, without variations in order to additional fields):
 
-```none
+```yaml
 x-kubernetes-int-or-string: true
 anyOf:
  - type: integer
@@ -489,13 +489,13 @@ anyOf:
 
 and
 
-```none
+```yaml
 x-kubernetes-int-or-string: true
 allOf:
  - anyOf:
  - type: integer
  - type: string
- - ... # zero or more
+ - # ... zero or more
 ...
 ```
 
@@ -522,12 +522,12 @@ properties:
 
 Here, the field `foo` holds a complete object, e.g.:
 
-```none
+```yaml
 foo:
  apiVersion: v1
  kind: Pod
  spec:
- ...
+ # ...
 ```
 
 Because `x-kubernetes-preserve-unknown-fields: true` is specified alongside, nothing is pruned.
@@ -796,8 +796,8 @@ rules are supported.
 
 For example:
 
-```none
- ...
+```yaml
+ # ...
  openAPIV3Schema:
  type: object
  properties:
@@ -809,7 +809,7 @@ For example:
  - rule: "self.replicas <= self.maxReplicas"
  message: "replicas should be smaller than or equal to maxReplicas."
  properties:
- ...
+ # ...
  minReplicas:
  type: integer
  replicas:
@@ -912,8 +912,8 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  `metadata.generateName`. This includes selection of fields in both the `spec` and `status` in the
  same expression:
 
- ```none
- ...
+ ```yaml
+ # ...
  openAPIV3Schema:
  type: object
  x-kubernetes-validations:
@@ -924,7 +924,7 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  properties:
  minReplicas:
  type: integer
- ...
+ # ...
  status:
  type: object
  properties:
@@ -936,8 +936,8 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  via `self.field` and field presence can be checked via `has(self.field)`. Null valued fields are treated as
  absent fields in CEL expressions.
 
- ```none
- ...
+ ```yaml
+ # ...
  openAPIV3Schema:
  type: object
  properties:
@@ -946,7 +946,7 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  x-kubernetes-validations:
  - rule: "has(self.foo)"
  properties:
- ...
+ # ...
  foo:
  type: integer
  ```
@@ -955,8 +955,8 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  are accessible via `self[mapKey]`, map containment can be checked via `mapKey in self` and all
  entries of the map are accessible via CEL macros and functions such as `self.all(...)`.
 
- ```none
- ...
+ ```yaml
+ # ...
  openAPIV3Schema:
  type: object
  properties:
@@ -965,7 +965,7 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
  x-kubernetes-validations:
  - rule: "self['xyz'].foo > 0"
  additionalProperties:
- ...
+ # ...
  type: object
  properties:
  foo:
@@ -975,12 +975,12 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
 - If the Rule is scoped to an array, the elements of the array are accessible via `self[i]` and
  also by macros and functions.
 
- ```none
- ...
+ ```yaml
+ # ...
  openAPIV3Schema:
  type: object
  properties:
- ...
+ # ...
  foo:
  type: array
  x-kubernetes-validations:
@@ -991,15 +991,15 @@ Xref: [Supported evaluation on CEL](https://github.com/google/cel-spec/blob/v0.6
 
 - If the Rule is scoped to a scalar, `self` is bound to the scalar value.
 
- ```none
- ...
+ ```yaml
+ # ...
  openAPIV3Schema:
  type: object
  properties:
  spec:
  type: object
  properties:
- ...
+ # ...
  foo:
  type: integer
  x-kubernetes-validations: