Generate Typescript Docs for @actions/artifact (#1595)

* autogenerate artifact documentation

* clean up comments for better autogen docs

packages/artifact/docs/generated/README.md

@@ -0,0 +1,40 @@
+@actions/artifact
+
+# @actions/artifact
+
+## Table of contents
+
+### Classes
+
+- [ArtifactNotFoundError](classes/ArtifactNotFoundError.md)
+- [DefaultArtifactClient](classes/DefaultArtifactClient.md)
+- [FilesNotFoundError](classes/FilesNotFoundError.md)
+- [GHESNotSupportedError](classes/GHESNotSupportedError.md)
+- [InvalidResponseError](classes/InvalidResponseError.md)
+
+### Interfaces
+
+- [Artifact](interfaces/Artifact.md)
+- [ArtifactClient](interfaces/ArtifactClient.md)
+- [DownloadArtifactOptions](interfaces/DownloadArtifactOptions.md)
+- [DownloadArtifactResponse](interfaces/DownloadArtifactResponse.md)
+- [FindOptions](interfaces/FindOptions.md)
+- [GetArtifactResponse](interfaces/GetArtifactResponse.md)
+- [ListArtifactsOptions](interfaces/ListArtifactsOptions.md)
+- [ListArtifactsResponse](interfaces/ListArtifactsResponse.md)
+- [UploadArtifactOptions](interfaces/UploadArtifactOptions.md)
+- [UploadArtifactResponse](interfaces/UploadArtifactResponse.md)
+
+### Variables
+
+- [default](README.md#default)
+
+## Variables
+
+### default
+
+• `Const` **default**: [`ArtifactClient`](interfaces/ArtifactClient.md)
+
+#### Defined in
+
+[src/artifact.ts:7](https://github.com/actions/toolkit/blob/e3764a5/packages/artifact/src/artifact.ts#L7)