Fix sync.py doc to reference "sync" instead of "helper"

sync/README.md

@@ -6,6 +6,6 @@ Google Cloud Platform credentials, and execute the following command:
 
 ```bash
 cd ..
-pip install -r helper/requirements.txt
-python helper/helper.py
+pip install -r requirements.txt
+python sync/sync.py
 ```

sync/config/README.md

@@ -5,4 +5,4 @@ See `pipelines.yaml` and `triggers.yaml` for more instructions. These two
 YAML files control the synchronization/curation from the `tektoncd/pipeline`
 and `tektoncd/triggers` repositories respectively.
 
-The YAML files here are used by the scripts in `../helper`.
+The YAML files here are used by the scripts in `../sync`.

templates/README.md

@@ -4,4 +4,4 @@ such as the documentation vault and the version switcher.
 At this moment the templates here are used to support the versioning of
 Tekton documentation, as the built-in system does not apply well to the
 structure of the Tekton project. The templates here are used by the scripts
-in `../helper`.
+in `../sync`.