Add option to configure workspace on host (#238)

Adds a new section to the configuration which is used
to control options when running in host mode.

The first option added is to allow configuration
of the location workspaces get created in.

Depends on ~~gitea/act#65~~
Will resolve #235

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/238
Reviewed-by: Jason Song <[email protected]>
Co-authored-by: Marius Zwicker <[email protected]>
Co-committed-by: Marius Zwicker <[email protected]>

internal/pkg/config/config.example.yaml

@@ -72,3 +72,8 @@ container:
   # default value is the value of DOCKER_HOST environment variable.
   # if DOCKER_HOST is not set, the default value is unix:///var/run/docker.sock
   docker_host: ""
+
+host:
+  # The parent directory of a job's working directory.
+  # If it's empty, $HOME/.cache/act/ will be used.
+  workdir_parent: