docs: Add JavaScript part into the style guide (#6607)

* docs: Add JavaScript part into the style guide

* Make dimensions go first

Author: igorlukanin

docs/content/Guides/Style-Guide.mdx

@@ -255,6 +255,53 @@ cubes:
         sub_query: true
 ```
 
+## JavaScript style guide
+
+* Indent with 2 spaces.
+* Don't use trailing semicolons.
+* Don't use trailing commas after last elements of arrays and objects. 
+* Use a new line to separate list items that are objects, where appropriate.
+* Make sure lines are no longer than 80 characters.
+* If quotes are needed around a string, use [backticks][wiki-backtick].
+
+### Example YAML
+
+```javascript
+cube(`users`, {
+  sql_table: `public.users`,
+
+  dimensions: {
+    id: {
+      sql: `id`,
+      type: `number`,
+      primary_key: true
+    },
+
+    city: {
+      sql: `city`,
+      type: `string`
+    },
+        
+    lifetime_value: {
+      sql: `${line_items.total_amount}`,
+      type: `number`,
+      sub_query: true
+    }
+  },
+
+  measures: {
+    count: {
+      type: `count`
+    },
+
+    total_orders_amount: {
+      sql: `${lifetime_value}`,
+      type: `sum`
+    }
+  }
+})
+```
+
 ## Credits
 
 This style guide was inspired in part by:
@@ -275,4 +322,5 @@ This style guide was inspired in part by:
 [ref-view-params]: /schema/reference/view#parameters
 [self-yaml]: #yaml-style-guide
 [self-sql]: #sql-style-guide
-[wiki-cte]: https://en.wikipedia.org/wiki/Hierarchical_and_recursive_queries_in_SQL#Common_table_expression
+[wiki-cte]: https://en.wikipedia.org/wiki/Hierarchical_and_recursive_queries_in_SQL#Common_table_expression
+[wiki-backtick]: https://en.wikipedia.org/wiki/Backtick