Update docs about format table function

docs/en/sql-reference/table-functions/format.md

@@ -6,25 +6,28 @@ sidebar_label: format
 
 # format
 
-Extracts table structure from data and parses it according to specified input format.
+Parses data from arguments according to specified input format. If structure argument is not specified, it's extracted from the data.
 
 **Syntax**
 
 ``` sql
-format(format_name, data)
+format(format_name, [structure], data)
 ```
 
 **Parameters**
 
 -   `format_name` — The [format](../../interfaces/formats.md#formats) of the data.
+-   `structure` - Structure of the table. Optional. Format 'column1_name column1_type, column2_name column2_type, ...'.
 -   `data` — String literal or constant expression that returns a string containing data in specified format
 
 **Returned value**
 
-A table with data parsed from `data` argument according specified format and extracted schema.
+A table with data parsed from `data` argument according to specified format and specified or extracted structure.
 
 **Examples**
 
+Without `structure` argument:
+
 **Query:**
 ``` sql
 SELECT * FROM format(JSONEachRow,
@@ -67,6 +70,29 @@ $$)
 └──────┴───────────────────┴──────────────┴────────────────────┴─────────┴──────────────────┴────────────────┘
 ```
 
+With `structure` argument:
+
+**Query:**
+```sql
+SELECT * FROM format(JSONEachRow, 'a String, b UInt32',
+$$
+{"a": "Hello", "b": 111}
+{"a": "World", "b": 123}
+{"a": "Hello", "b": 112}
+{"a": "World", "b": 124}
+$$)
+```
+
+**Result:**
+```response
+┌─a─────┬───b─┐
+│ Hello │ 111 │
+│ World │ 123 │
+│ Hello │ 112 │
+│ World │ 124 │
+└───────┴─────┘
+```
+
 **See Also**
 
 -   [Formats](../../interfaces/formats.md)