Add doc for file-format option (#342) (#343)

* Add doc for file-format

* Update index.mdx

* Apply suggestions from code review

---------

Co-authored-by: ziyi chen <chenziyi990424@gmail.com>

Author: prrao87

src/content/docs/cypher/query-clauses/load-from.md

@@ -144,7 +144,20 @@ You can also see the details of any warnings generated by the skipped lines usin
 See the [ignoring erroneous rows section of `COPY FROM`](import#ignore-erroneous-rows) for more details.
 
 ## Scan Data Formats
-Load from can scan several raw or in-memory file formats, such as CSV, Parquet, Pandas, Polars, Arrow tables, and JSON.
+`LOAD FROM` can scan several raw or in-memory file formats, such as CSV, Parquet, Pandas, Polars, Arrow tables, and JSON.
+
+### File format detection
+`Load from` determines the file format based on the file extension if the `file_format` option is not given. For instance, files with a `.csv` extension are automatically recognized as CSV format.
+
+If the file format cannot be inferred from the extension, or if you need to override the default sniffing behaviour, the `file_format` option can be used.
+
+For example, to load a CSV file that has a `.tsv` extension (for tab-separated data), you must explicitly specify the file format using the `file_format` option, as shown below:
+```
+LOAD FROM 'data.tsv' (file_format='csv')
+RETURN *
+```
+
+
 Below we give examples of using `LOAD FROM` to scan data from each of these formats. We assume `WITH HEADERS`
 is not used in the examples below, so we discuss how Kùzu infers the variable names and data types of
 that bind to the scanned tuples.

src/content/docs/import/index.mdx

@@ -52,6 +52,15 @@ The following sections show how to bulk import data using `COPY FROM` on various
 
 </CardGrid>
 
+:::caution[Note]
+Similar to the [LOAD FROM](/cypher/query-clauses/load-from.md) clause, the `COPY FROM` clause determines the file format based on the file extension if the `file_format` option is not provided. Alternatively, the `file_format` option can be used in the `COPY FROM` clause to explicitly specify the file format.
+
+Example: To copy from a file ending with an arbitrary extension like `.dsv`, use the `file_format = 'csv'` option to explicitly tell Kùzu to treat the file as a `CSV` file.
+```
+COPY person FROM 'person.dsv' (file_format = 'csv')
+```
+:::
+
 ## `COPY FROM` a partial subset
 
 In certain cases, you may only want to partially fill your Kùzu table using the data from your input