Formalize processes for regularly upgrading website tools

**This is a Feature Request**

Currently there isn't a process or automation that covers upgrading the tools we use for the kubernetes.io website. Specifically Hugo and our theme Docsy.

**What would you like to be added**

We should determine a list of tools we need to keep updated, and then create a way to trigger updating the tools at an interval that makes sense for the project and maintainer bandwidth. Either by some automation or manually upgrading the tools

We should also make sure we have tool upgrade processes documented, especially any differences with the tools upgrade docs. (these could already exist, but i'm not sure where they are located so i included it here :) )

**Why is this needed**

Previously these kinds of updates were triggered by bugs in the tools. Ideally, we'd also have a way to upgrade when we want to to access new features or improvements.

**Comments**
Some related links:
* Slack thread about this topic: https://kubernetes.slack.com/archives/C1J0BPD2M/p1663961513084469
* Write up on upgrading hugo from the last time we upgraded: https://github.com/kubernetes/website/pull/23434

Start by reading the linked write-up in pull request 23434 and the referenced Slack thread, then locate any existing Hugo and Docsy upgrade documentation. Inventory the tools and agree on a manual or automated upgrade cadence. Done means the upgrade process, tool list, and trigger or schedule are documented.

Written by the indexing model from the issue text.