Set optional fields (#243)

Author: thomaspoignant

docs/data_collection/file.md

@@ -26,8 +26,8 @@ ffclient.Config{
 | Field  | Description  |
 |---|---|
 |`OutputDir`   | OutputDir is the location of the directory where to store the exported files.<br>It should finish with a `/`.  |
-|`Format`   |   Format is the output format you want in your exported file.<br>Available format: **`JSON`**, **`CSV`**.<br>**Default: `JSON`** |
-|`Filename`   | Filename is the name of your output file.<br>You can use a templated config to define the name of your exported files.<br>Available replacement are `{{ .Hostname}}`, `{{ .Timestamp}}` and `{{ .Format}}`<br>**Default: `flag-variation-{{ .Hostname}}-{{ .Timestamp}}.{{ .Format}}`**|
-|`CsvTemplate`   |   CsvTemplate is used if your output format is CSV.<br>This field will be ignored if you are using another format than CSV.<br>You can decide which fields you want in your CSV line with a go-template syntax, please check [internal/exporter/feature_event.go](https://github.com/thomaspoignant/go-feature-flag/blob/main/internal/exporter/feature_event.go) to see what are the fields available.<br>**Default:** `{{ .Kind}};{{ .ContextKind}};{{ .UserKey}};{{ .CreationDate}};{{ .Key}};{{ .Variation}};{{ .Value}};{{ .Default}}\n` |
+|`Format`   |   _(Optional)_ Format is the output format you want in your exported file.<br>Available format: **`JSON`**, **`CSV`**.<br>**Default: `JSON`** |
+|`Filename`   | _(Optional)_ Filename is the name of your output file.<br>You can use a templated config to define the name of your exported files.<br>Available replacement are `{{ .Hostname}}`, `{{ .Timestamp}}` and `{{ .Format}}`<br>**Default: `flag-variation-{{ .Hostname}}-{{ .Timestamp}}.{{ .Format}}`**|
+|`CsvTemplate`   | _(Optional)_ CsvTemplate is used if your output format is CSV.<br>This field will be ignored if you are using another format than CSV.<br>You can decide which fields you want in your CSV line with a go-template syntax, please check [internal/exporter/feature_event.go](https://github.com/thomaspoignant/go-feature-flag/blob/main/internal/exporter/feature_event.go) to see what are the fields available.<br>**Default:** `{{ .Kind}};{{ .ContextKind}};{{ .UserKey}};{{ .CreationDate}};{{ .Key}};{{ .Variation}};{{ .Value}};{{ .Default}}\n` |
 
 Check the [godoc for full details](https://pkg.go.dev/github.com/thomaspoignant/[email protected]/ffexporter#File).