Document artifacts validation + reformat a few things

.github/CODEOWNERS

@@ -1 +1,2 @@
-* @paper-spa/pages
+# Default PR reviewers
+* @actions/pages

.github/release-drafter.yml

@@ -1,40 +1,40 @@
 ---
-name-template: 'v$RESOLVED_VERSION'
-tag-template: 'v$RESOLVED_VERSION'
+name-template: "v$RESOLVED_VERSION"
+tag-template: "v$RESOLVED_VERSION"
 template: |
   # Changelog
 
   $CHANGES
 
   See details of [all code changes](https://github.com/$OWNER/$REPOSITORY/compare/$PREVIOUS_TAG...v$RESOLVED_VERSION) since previous release.
 categories:
-  - title: '🚀 Features'
+  - title: "🚀 Features"
     labels:
-      - 'feature'
-      - 'enhancement'
-  - title: '🐛 Bug Fixes'
+      - "feature"
+      - "enhancement"
+  - title: "🐛 Bug Fixes"
     labels:
-      - 'fix'
-      - 'bugfix'
-      - 'bug'
-  - title: '🧰 Maintenance'
+      - "fix"
+      - "bugfix"
+      - "bug"
+  - title: "🧰 Maintenance"
     labels:
-      - 'infrastructure'
-      - 'automation'
-      - 'documentation'
-  - title: '🏎 Performance'
-    label: 'performance'
-change-template: '- $TITLE @$AUTHOR (#$NUMBER)'
+      - "infrastructure"
+      - "automation"
+      - "documentation"
+  - title: "🏎 Performance"
+    label: "performance"
+change-template: "- $TITLE @$AUTHOR (#$NUMBER)"
 version-resolver:
   major:
     labels:
-      - 'type: breaking'
+      - "type: breaking"
   minor:
     labels:
-      - 'type: enhancement'
+      - "type: enhancement"
   patch:
     labels:
-      - 'type: bug'
-      - 'type: maintenance'
-      - 'type: documentation'
-  default: patch
+      - "type: bug"
+      - "type: maintenance"
+      - "type: documentation"
+  default: patch

README.md

@@ -4,14 +4,28 @@ A composite action for packaging and uploading artifact that can be deployed to
 
 # Scope
 
-⚠️ Official support for building Pages with Actions is in public beta at the moment. The scope is currently limited to **public repositories only**.
+⚠️ Official support for building Pages with Actions is in public beta at the moment.
 
 # Usage
 
 See [action.yml](action.yml)
 
 <!-- TODO: document custom workflow -->
 
+# Artifact validation
+
+While using this action is optional, we highly recommend it since it takes care of producing (mostly) valid artifacts.
+
+A Pages artifact must:
+
+- Be called `github-pages`
+- Be a single [`gzip` archive][gzip] containing a single [`tar` file][tar]
+
+The [`tar` file][tar] must:
+
+- be under 10GB in size
+- not contain any symbolic or hard links
+
 # Release instructions
 
 In order to release a new version of this Action:
@@ -36,4 +50,6 @@ The scripts and documentation in this project are released under the [MIT Licens
 <!-- references -->
 [pages]: https://pages.github.com
 [draft-release]: .github/workflows/draft-release.yml
-[release]: .github/workflows/release.yml
+[release]: .github/workflows/release.yml
+[gzip]: https://en.wikipedia.org/wiki/Gzip
+[tar]: https://en.wikipedia.org/wiki/Tar_(computing)

action.yml

@@ -1,14 +1,14 @@
-name: 'Upload Pages artifact'
-description: 'A composite action that prepares your static assets to be deployed to GitHub Pages'
+name: "Upload Pages artifact"
+description: "A composite action that prepares your static assets to be deployed to GitHub Pages"
 inputs:
   path:
-    description: 'Path of the directoring containing the static assets.'
+    description: "Path of the directoring containing the static assets."
     required: true
-    default: '_site/'
+    default: "_site/"
   retention-days:
-    description: 'Duration after which artifact will expire in days.'
+    description: "Duration after which artifact will expire in days."
     required: false
-    default: '1'
+    default: "1"
 runs:
   using: composite
   steps: