formatter: tsv: Add TSV formatter plugin documentation

Signed-off-by: Hiroshi Hatake <hatake@clear-code.com>

Author: cosmo0920

plugins/formatter/README.md

@@ -67,6 +67,7 @@ how to develop a custom formatter.
 -   [`msgpack`](/plugins/formatter/msgpack.md)
 -   [`hash`](/plugins/formatter/hash.md)
 -   [`single_value`](/plugins/formatter/single_value.md)
+-   [`tsv`](/plugins/formatter/tsv.md)
 
 
 ## List of Output/Filter Plugins with Formatter Support

plugins/formatter/tsv.md

@@ -0,0 +1,76 @@
+# `tsv` Formatter Plugin
+
+The `tsv` formatter plugin converts an event as TSV.
+
+```text
+value1[delimiter]value2[newline]
+```
+
+
+## Parameters
+
+-   [Common Parameters](/configuration/plugin-common-parameters.md)
+-   [Format section configurations](/configuration/format-section.md)
+
+### `keys`
+
+| type            | default  | version |
+|:----------------|:---------|:--------|
+| array of string | `nil`    | 0.14.0  |
+
+Specifies the output fields. It is a required parameter.
+
+### `delimiter`
+
+| type   | default    | version |
+|:-------|:-----------|:--------|
+| string | `\t` (TAB) | 0.14.0  |
+
+Delimiter for the fields.
+
+### `add_newline`
+
+| type | default | version |
+|:-----|:--------|:--------|
+| bool | `true`  | 0.14.12 |
+
+Adds `\n` to the result.
+
+### `newline`
+
+| type | default                                         | version |
+|:-----|:------------------------------------------------|:--------|
+| enum | `lf (for non-Windows)` or `crlf (for Windows)`  | 1.11.5  |
+
+
+Specify newline characters.
+
+## Example
+
+```text
+tag:    app.event
+time:   1362020400
+record: {"host":"192.168.0.1","size":777,"method":"PUT"}
+```
+
+This incoming event is formatted to:
+
+In non-Windows:
+
+```text
+192.168.0.1\t777\tPUT\n
+```
+
+In non-Windows:
+
+```text
+192.168.0.1\t777\tPUT\r\n
+```
+
+------------------------------------------------------------------------
+
+If this article is incorrect or outdated, or omits critical information, please
+[let us know](https://github.com/fluent/fluentd-docs-gitbook/issues?state=open).
+[Fluentd](http://www.fluentd.org/) is an open-source project under
+[Cloud Native Computing Foundation (CNCF)](https://cncf.io/). All components are
+available under the Apache 2 License.