docs: add pre-release section and link ArtifactHub annotations

Document how the action handles pre-release tags (-rc pattern),
including the prerelease annotation and skipped changelog generation.
Link "ArtifactHub annotations" to the official documentation.

Co-authored-by: Copilot <copilot@github.com>

README.md

@@ -1,6 +1,8 @@
 # ah-annotation
 
-GitHub Action to generate ArtifactHub changelog annotations from Git commit history and add them to `Chart.yaml`.
+GitHub Action to generate [ArtifactHub
+annotations](https://artifacthub.io/docs/topics/annotations/helm/#supported-annotations) from Git commit history and add
+them to `Chart.yaml`.
 
 The action parses conventional commit messages between two Git tags and produces an `artifacthub.io/changes` annotation.
 Pre-release tags (matching `-rc`) are detected automatically and result in an `artifacthub.io/prerelease` annotation
@@ -17,7 +19,7 @@ steps:
   - uses: actions/checkout@v7.0.1
     with:
       fetch-depth: 0
-  - uses: volker.raschek/ah-annotations@v0.0.1
+  - uses: volker.raschek/ah-annotations@v0.1.1
 ```
 
 ### Explicit tags
@@ -29,7 +31,7 @@ steps:
   - uses: actions/checkout@v7.0.1
     with:
       fetch-depth: 0
-  - uses: volker.raschek/ah-annotations@v0.0.1
+  - uses: volker.raschek/ah-annotations@v0.1.1
     with:
       old-tag: v1.0.0
       new-tag: v2.0.0
@@ -42,7 +44,7 @@ steps:
 | `chart-path`       | no       | `${{ github.workspace }}/Chart.yaml` | Path to the Helm chart file.               |
 | `old-tag`          | no       | auto-detected                        | Start tag for changelog generation.        |
 | `new-tag`          | no       | auto-detected                        | End tag for changelog generation.          |
-| `yq-version`       | no       | `v4.53.3`                            | Version of yq to install.                  |
+| `yq-version`       | no       | `v4.44.6`                            | Version of yq to install.                  |
 | `yq-arch`          | no       | auto-detected                        | Architecture of yq binary to download.     |
 | `yq-os`            | no       | auto-detected                        | Operating system of yq binary to download. |
 | `yq-binary-name`   | no       | `yq`                                 | Name of the yq binary to download.         |
@@ -54,6 +56,17 @@ steps:
 - A `Chart.yaml` file must exist at the path specified by `chart-path`.
 - Commit messages must follow the [Conventional Commits](https://www.conventionalcommits.org/) format.
 
+## Pre-releases
+
+Tags matching the pattern `-rc` (e.g. `v1.0.0-rc.1`, `v2.0.0-rc`) are treated as pre-releases.
+When `new-tag` is a pre-release tag, the action:
+
+1. Sets `artifacthub.io/prerelease: "true"` in `Chart.yaml`.
+2. Skips changelog generation entirely.
+
+When auto-detecting tags (no explicit `old-tag`/`new-tag`), the action ignores pre-release tags and selects the two
+most recent stable tags instead.
+
 ## Commit type mapping
 
 | Commit type                                      | ArtifactHub kind |

install-yq.sh

@@ -2,7 +2,7 @@
 
 set -euo pipefail
 
-internal_yq_version=v4.53.3 # renovate: datasource=github-releases depName=mikefarah/yq versioning=semver
+internal_yq_version=v4.44.6 # renovate: datasource=github-releases depName=mikefarah/yq versioning=semver
 
 # Use :- for unset and handle empty strings from composite action inputs
 YQ_BINARY_NAME="${YQ_BINARY_NAME:="yq"}"