chore: Configure Renovate (#59)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

Welcome to [Renovate](https://togithub.com/renovatebot/renovate)! This
is an onboarding PR to help you understand and configure settings before
regular Pull Requests begin.

🚦 To activate Renovate, merge this Pull Request. To disable Renovate,
simply close this Pull Request unmerged.



---
### Detected Package Files

 * `charts/athens-proxy/Chart.yaml` (regex)

### Configuration Summary

Based on the default config's presets, Renovate will:

  - Start dependency updates only once this onboarding PR is merged
  - Show all Merge Confidence badges for pull requests.
  - Enable Renovate Dependency Dashboard creation.
- Use semantic commit type `fix` for dependencies and `chore` for all
others if semantic commits are in use.
- Ignore `node_modules`, `bower_components`, `vendor` and various
test/tests directories.
  - Group known monorepo packages together.
  - Use curated list of recommended non-monorepo package groupings.
  - Apply crowd-sourced package replacement rules.
  - Apply crowd-sourced workarounds for known problems with packages.

🔡 Do you want to change how Renovate upgrades your dependencies? Add
your custom config to `renovate.json` in this branch. Renovate will
update the Pull Request description the next time it runs.

---

### What to Expect

With your current configuration, Renovate will create 1 Pull Request:

<details>
<summary>chore(deps): update gomods/athens docker tag to
v0.13.3</summary>

  - Schedule: ["at any time"]
  - Branch name: `renovate/gomods-athens-0.x`
  - Merge into: `main`
- Upgrade [gomods/athens](https://togithub.com/gomods/athens) to
`v0.13.3`


</details>


---

❓ Got questions? Check out Renovate's
[Docs](https://docs.renovatebot.com/), particularly the Getting Started
section.
If you need any further assistance then you can also [request help
here](https://togithub.com/renovatebot/renovate/discussions).


---

This PR has been generated by [Mend
Renovate](https://www.mend.io/free-developer-tools/renovate/). View
repository job log
[here](https://developer.mend.io/github/gomods/athens-charts).


<!--renovate-config-hash:2ca40c2491a5933eaacc41c896d2aac187f212f67f92188cb32452c3d00d289c-->

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: DrPsychick <[email protected]>

README.md

@@ -13,8 +13,12 @@ On Artifact Hub: https://artifacthub.io/packages/search?org=gomods
 * Create issues, create PRs, ... let's make this better together.
 * See [Contributing](CONTRIBUTING.md)
 
-### Publish new chart version
-Change the version in `Chart.yaml`. When the change is merged to main, it will trigger creating a release.
+### Publish a new chart version
+Create a PR that changes the version in `Chart.yaml`. When the change is merged to main, it will trigger creating a release.
 
 A version bump is not enforced, so changes are collected on branch `main` and only released when the version of 
 the chart is changed.
+
+To release the chart with a new Athens version, the PR that bumps the Athens image version is created automatically.
+This can be merged to `main` without impact for the current release. After this, create a PR that updates the Chart
+version to release the chart using the new Athens image version.

renovate.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "config:recommended"
+  ],
+  "enabledManagers": ["regex", "helmv3"],
+  "regexManagers": [
+    {
+      "description": "Update athens image reference in Chart.yaml",
+      "fileMatch": ["^charts\\/athens-proxy\\/Chart\\.yaml$"],
+      "matchStrings": [
+        "appVersion:\\s+(?<currentValue>.*)"
+      ],
+      "depNameTemplate": "gomods/athens",
+      "datasourceTemplate": "docker"
+    }
+  ]
+}