Updating voltha-2.8 release, bumping to 2.10 and using master for all references

Change-Id: I5dbef01fb43f95eb5663963d61409ff07b59e2c3
diff --git a/overview/deployment_environment.rst b/overview/deployment_environment.rst
index 9f4815b..cded591 100644
--- a/overview/deployment_environment.rst
+++ b/overview/deployment_environment.rst
@@ -49,7 +49,7 @@
 You can read more about VOLTHA deployments in:
 
 - :doc:`lab_setup`
-- `Deployment with HELM <./../voltha-helm-charts/README.md>`_
+- `Deployment with HELM <../voltha-helm-charts/README.md>`_
 
 .. toctree::
    :maxdepth: 1
@@ -57,4 +57,4 @@
    :glob:
 
    ./lab_setup.rst
-   Deploy VOLTHA <./../voltha-helm-charts/README.md>
+   Deploy VOLTHA <../voltha-helm-charts/README.md>