1.0: add max_line_size explanation

Signed-off-by: Kentaro Hayashi <hayashi@clear-code.com>

Author: kenhys

input/tail.md

@@ -230,6 +230,18 @@ This value should be equal or greater than 8192.
 
 If you work with a big cluster with high volume of log, you can use this parameter to avoid network saturation and make it easier to calculate the max throughput per node. To restrict shipping log volumes per second, set a positive number.
 
+### `max_line_size`
+
+| type | default | version |
+| :--- | :--- | :--- |
+| size | nil | 1.14.4 |
+
+The maximum line length which should be ignored.
+The longer line is just skipped.
+
+If you see `BufferChunkOverflowError` exception frequently, it means that incoming data is too long.
+If such a long line is unexpected incoming data and want to ignore it, then set a smaller value than `chunk_limit_size` in `<buffer>` section.
+
 ### `multiline_flush_interval`
 
 | type | default | version |