Add README

.markdown-style.rb

@@ -0,0 +1,2 @@
+all # Import all rules
+exclude_rule "MD013" # Ignore Line length

.mdlrc

@@ -0,0 +1,2 @@
+style "#{File.dirname(__FILE__)}/.markdown-style.rb"
+git_recurse true

README.md

@@ -0,0 +1,31 @@
+# verdigado pre-commit container
+
+A container image to include all dependencies (and a warmed up cache) used in our [`pre-commit`](https://pre-commit.com/) hooks/CI steps to speed up execution.
+
+If you see any pre-commit CI jobs installing dependencies:
+
+- Make sure to execute `pre-commit` using this container
+- Add the hook to this repo's `.pre-commit-config.yaml`
+- Optionally install dependencies in the `Dockerfile` with the versions set up for `Renovate`
+
+## Usage
+
+In your `.woodpecker.yaml`, adapt and add the following block:
+
+```yaml
+steps:
+  check-pre-commit:
+    image: git.verdigado.com/verdigado-images/container-pre-commit:latest
+    environment:
+      - SKIP=no-commit-to-branch # Ignore "don't commit to protected branch" check
+    commands:
+      - pre-commit run --all-files
+```
+
+If renovate is set up, it'll add and update the pinned digest/hash of the image.
+
+## Development
+
+If you need to copy files into the container, don't forget to add exclusions to the general _exclude all_ in `.dockerignore`.
+
+To update the base image (like `3.12.4-alpine3.20` to a newer Alpine version), manual work is still required. In the `Dockerfile`, update the Alpine version for the image, the renovate comments (`# renovate: datasource=repology depName=alpine_3_20/gcc versioning=loose`), and the package versions for that OS version from the repo (Like on the [Alpine Package Page for gcc](https://pkgs.alpinelinux.org/packages?name=gcc&branch=v3.20&repo=&arch=x86_64)).