docs: add example to validate doc

Author: 0hsn

docs/references/validate-spec.md

@@ -10,7 +10,6 @@ Validate specification document supports `version: default:validate:0.7.2` versi
   <summary>All supported nodes in Validate specification document</summary>
 
   ```yml
-  ---
   version: default:validate:0.7.2
 
   variables:
@@ -43,12 +42,36 @@ Validate specification document supports `version: default:validate:0.7.2` versi
 
 ## `version` (<small>*`required`*</small>)
 
-This is a top-level block that defines the document version. Read details of [_version reference_](/docs/references/version) here.
+This is a top-level block that defines the spec. document version. Read details of [_version reference_](/docs/references/version) here.
+
+```yml {1}
+version: default:validate:0.7.2
+
+data:
+  ...
+
+asserts:
+  ...
+...
+```
 
 ## `variables`
 
 `variables` is a top-level block that defines local variables. These variables are not accessible outside of this file scope.
 
+```yml {3-4}
+version: default:validate:0.7.2
+
+variables:
+  Name: "Variable Value"
+
+data:
+  code: 200
+
+asserts:
+  ...
+```
+
 Read details of [*variables*](/docs/references/variables) here.
 
 ## `data`
@@ -57,14 +80,19 @@ Read details of [*variables*](/docs/references/variables) here.
 
 `data` only supports YAML maps, where keys holds strings and values contains YAML collection (dictionary / hashmap) or scaler values.
 
-```yml
+```yml {3-4}
+version: default:validate:0.7.2
+
 data:
   code: 200
+
+asserts:
+  ...
 ```
 
 ## `asserts` (<small>*`required`*</small>)
 
-This is a top-level block to defines list of assertions. This assertions can target both data and variables.
+This is a top-level block to defines list of assertions. These assertions can target both data and variables.
 
 Data type for `asserts` node is list of assert item.
 
@@ -73,12 +101,22 @@ Data type for `asserts` node is list of assert item.
 Assert items define assertion for one specific case. It looks like following:
 
 ```yml
+version: default:validate:0.7.2
+
+data:
+  code: 200
+
+variables:
+  Name: "Variable Value"
+
 asserts:
   - type: Equal
     actual: <% code %>
     expected: 200
     msg_pass: 'Response was successful'
     msg_fail: 'Response was unsuccessful'
+
+  - # [assertItem] 
 ```
 
 Explanation of possible nodes: