add autogenerated list of features to top-level readme

.github/workflows/update-main-readme.yml

@@ -0,0 +1,27 @@
+name: Update main readme
+on:
+  push:
+    branches: "main"
+    paths:
+      - .github/workflows/update-main-readme.yml
+  pull_request:
+    paths:
+      - .github/workflows/update-main-readme.yml
+  schedule:
+    # https://crontab.guru/daily
+    - cron: "0 0 * * *"
+  workflow_call:
+  workflow_dispatch:
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+jobs:
+  update-main-readme:
+    concurrency: ${{ github.ref }}-write
+    permissions:
+      contents: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: devcontainers-community/update-collection-readme@v1
+      - uses: stefanzweifel/git-auto-commit-action@v4

README.md

@@ -1,11 +1,20 @@
 # Dev Container Features: Self Authoring Template
 
-> This repo provides a starting point and example for creating your own custom [dev container Features](https://containers.dev/implementors/features/), hosted for free on GitHub Container Registry.  The example in this repository follows the [dev container Feature distribution specification](https://containers.dev/implementors/features-distribution/).  
+> This repo provides a starting point and example for creating your own custom [dev container Features](https://containers.dev/implementors/features/), hosted for free on GitHub Container Registry.  The example in this repository follows the [dev container Feature distribution specification](https://containers.dev/implementors/features-distribution/).
 >
 > To provide feedback to the specification, please leave a comment [on spec issue #70](https://github.com/devcontainers/spec/issues/70). For more broad feedback regarding dev container Features, please see [spec issue #61](https://github.com/devcontainers/spec/issues/61).
 
 ## Example Contents
 
+<!-- prettier-ignore-start -->
+<!-- START_FEATURE_LIST -->
+
+- **My Favorite Color** - A feature to remind you of your favorite color
+- **Hello, World!** - A hello world feature
+
+<!-- END_FEATURE_LIST -->
+<!-- prettier-ignore-end -->
+
 This repository contains a _collection_ of two Features - `hello` and `color`. These Features serve as simple feature implementations.  Each sub-section below shows a sample `devcontainer.json` alongside example usage of the Feature.
 
 ### `hello`
@@ -52,7 +61,7 @@ my favorite color is green
 
 ## Repo and Feature Structure
 
-Similar to the [`devcontainers/features`](https://github.com/devcontainers/features) repo, this repository has a `src` folder.  Each Feature has its own sub-folder, containing at least a `devcontainer-feature.json` and an entrypoint script `install.sh`. 
+Similar to the [`devcontainers/features`](https://github.com/devcontainers/features) repo, this repository has a `src` folder.  Each Feature has its own sub-folder, containing at least a `devcontainer-feature.json` and an entrypoint script `install.sh`.
 
 ```
 ├── src
@@ -113,13 +122,13 @@ Features are individually versioned by the `version` attribute in a Feature's `d
 
 ### Publishing
 
-> NOTE: The Distribution spec can be [found here](https://containers.dev/implementors/features-distribution/).  
+> NOTE: The Distribution spec can be [found here](https://containers.dev/implementors/features-distribution/).
 >
 > While any registry [implementing the OCI Distribution spec](https://github.com/opencontainers/distribution-spec) can be used, this template will leverage GHCR (GitHub Container Registry) as the backing registry.
 
-Features are meant to be easily sharable units of dev container configuration and installation code.  
+Features are meant to be easily sharable units of dev container configuration and installation code.
 
-This repo contains a **GitHub Action** [workflow](.github/workflows/release.yaml) that will publish each Feature to GHCR. 
+This repo contains a **GitHub Action** [workflow](.github/workflows/release.yaml) that will publish each Feature to GHCR.
 
 *Allow GitHub Actions to create and approve pull requests* should be enabled in the repository's `Settings > Actions > General > Workflow permissions` for auto generation of `src/<feature>/README.md` per Feature (which merges any existing `src/<feature>/NOTES.md`).