Update index.md (#918)

docs/sources/tutorials/first-components-and-stdlib/index.md

@@ -101,7 +101,7 @@ Each component has a link to its documentation, which contains a description of
 {{< /admonition >}}
 
 This pipeline has two components: `local.file` and `prometheus.remote_write`.
-The `local.file` component is configured with a single argument, `path`, which is set by calling the [env][] standard library function to retrieve the value of the `HOME` environment variable and concatenating it with the string `"file.txt"`.
+The `local.file` component is configured with a single argument, `filename`, which is set by calling the [env][] standard library function to retrieve the value of the `HOME` environment variable and concatenating it with the string `"file.txt"`.
 The `local.file` component has a single export, `content`, which contains the contents of the file.
 
 The `prometheus.remote_write` component is configured with an `endpoint` block, containing the `url` attribute and a `basic_auth` block.