[DOCS] Docs changes for overridden delimiter in find_file_structure

Docs for elastic#55735

docs/reference/ml/anomaly-detection/apis/find-file-structure.asciidoc

@@ -80,7 +80,10 @@ chosen.
  the character used to delimit the values in each row. Only a single character
  is supported; the delimiter cannot have multiple characters. If this parameter
  is not specified, the structure finder considers the following possibilities:
- comma, tab, semi-colon, and pipe (`|`).
+ comma, tab, semi-colon, and pipe (`|`). If you specify a delimiter explicitly
+ then the format determination will tolerate up to 10% of rows having a
+ different number of columns to the first row. (Without overrides all rows
+ must have the same number of fields for a delimited format to be detected.)
 
 `explain`::
  (Optional, boolean) If this parameter is set to `true`, the response includes
@@ -90,7 +93,12 @@ chosen.
 `format`::
  (Optional, string) The high level structure of the file. Valid values are
  `ndjson`, `xml`, `delimited`, and `semi_structured_text`. If this parameter is
- not specified, the structure finder chooses one.
+ not specified, the structure finder chooses one. If the format is overridden
+ to `delimited` but no explicit delimiter is specified then the format
+ determination will tolerate up to 5% of rows having a different number of
+ columns to the first row for each of the following possible delimiters:
+ comma, tab, semi-colon, and pipe (`|`). (Without overrides all rows
+ must have the same number of fields for a delimited format to be detected.)
 
 `grok_pattern`::
  (Optional, string) If you have set `format` to `semi_structured_text`, you can