Changed json blocks to use yaml tag (#2477)

Author: technige

api-design-guidelines/data-modelling.md

@@ -8,7 +8,7 @@ JSON objects must be conceptually treated as **unordered**. Maintaining order of
 
 If preservation of order is important, such ordering information should be represented separately. The examples below shows a plain (unordered) object alongside three alternative representations which also provide ordering detail.
 
-```json
+```yaml
 // Plain object (unordered)
 {
   "one": "eins",
@@ -49,15 +49,15 @@ JSON objects and query string parameters must not use duplicate keys. The behavi
 Nulls are sometimes used to mark a value as "missing" or "not available". Instead of returning `null` as a value in JSON prefer to omit the field in the response. Empty strings (`""`) should similarly not be used to denote a missing string value as they can be confused for an explicit value of the empty string. It is fine to accept `null` in the request if they have special semantics such as unsetting a value. Otherwise fields that would have null or empty string values should also be omitted in the request.
 
 - DON'T:
-  ```json
+  ```yaml
   {"key1": 1, "key2": null} 
   ```
 - DON'T:
-  ```json
+  ```yaml
   {"key1": 1, "key2": ""}
   ```
 - DO:
-  ```json
+  ```yaml
   {"key1": 1}
   ```
 
@@ -107,35 +107,35 @@ Modelling objects that are a mix between static and dynamic keys is more complex
 
 An example of mixed static and dynamic keys can be seen in the `indices.field_usage_stats` endpoint response:
 
-```json
+```yaml
 {
   "_shards": {
     "total": 1,
     "successful": 1,
     "failed": 0
   },
-  "my-index": { ... }
+  "my-index": {...}
 }
 ```
 
 The key `"my-index"` is user-defined wheras `"_shards"` is static. This API would be easier to model by keeping all dynamic keys in their own object:
 
-```json
+```yaml
 {
   "_shards": {
     "total": 1,
     "successful": 1,
     "failed": 0
   },
   "indices": {
-     "my-index": { ... }
+     "my-index": {...}
   }
 }
 ```
 
 Or better yet, to completely avoid using dynamic keys the user-defined value can be a property value within the object itself:
 
-```json
+```yaml
 {
   "_shards": {
     "total": 1,
@@ -152,7 +152,7 @@ Or better yet, to completely avoid using dynamic keys the user-defined value can
 
 Sometimes an API accepts an object but the keys are determined by what "kind/variant" of the object is intended. An example of this is aggregations, queries, and pipeline steps. There are two ways the Elasticsearch API handles this situation. The first method is using an **internal variant type** property like "type" with analyzers:
 
-```json
+```yaml
 {
   "type": "snowball",
   "stopwords": ["if", "and", "but"]
@@ -161,7 +161,7 @@ Sometimes an API accepts an object but the keys are determined by what "kind/var
 
 The second is using **external variants** where the inner object is wrapped with an object with a single key containing the kind of the inner object. This example changes the analyzer from above to use an external variant:
 
-```json
+```yaml
 {
   "snowball": {
     "stopwords": ["if", "and", "but"]
@@ -254,7 +254,7 @@ Many of our APIs support users supplying values in multiple different formats. F
 
 For the sake of user experience we should accept values in different formats. For values that accept multiple formats the format should be explicitly set by users so Elasticsearch can interpret and validate the value based on the given format. For example:
 
-```json
+```yaml
 {"type": "date", "format": "yyyy-MM-dd HH:mm:ss"}
 ```
 

api-design-guidelines/naming.md

@@ -54,7 +54,7 @@ Some programming languages place special meaning on underscore prefixes and suff
 
 See the below example with a JSON object with two properties `nodes` and `_nodes`:
 
-```json
+```yaml
 {
   "nodes": {...},
   "_nodes": {...}
@@ -63,7 +63,7 @@ See the below example with a JSON object with two properties `nodes` and `_nodes
 
 For this API the generated structure in some programming languages would have a clash between the names of the two properties which would require inventing a name for one of the properties. Diversions from the API as it is on the wire are likely to cause confusion for users and should be avoided if possible. Instead these properties could be named more semantically as follows:
 
-```json
+```yaml
 {
   "nodes": {...},
   "node_info": {...}

api-design-guidelines/requests-responses.md

@@ -111,7 +111,7 @@ This principle allows for simpler consumer code that neither has to remember sta
 
 An example of this is the datafeeds API which accepts either a string or list of strings for indices but always returns a list of strings:
 
-```json
+```yaml
 PUT /_ml/datafeeds/feed-id
 {
   "indices": "index-name", // Input is a string.
@@ -139,7 +139,7 @@ The `name` of the function is typically restricted to alphanumeric characters an
 
 Functions also only allow a single return / response type which is the "nominal successful response". Error responses can vary based on status code but at a minimum should match the following structure:
 
-```json
+```yaml
 {
   "type": "error type",
   "reason": "<human readable message>",