Deploy: Improve documentation

.env.example.githubpages

@@ -1,12 +1,7 @@
-# Those variables stay empty
-# because we don't use Keystatic on Github Pages.
-KEYSTATIC_GITHUB_CLIENT_ID=     # Empty on Github Pages
-KEYSTATIC_GITHUB_CLIENT_SECRET= # Empty on Github Pages
-KEYSTATIC_SECRET=               # Empty on Github Pages
-PUBLIC_KEYSTATIC_GITHUB_APP_SLUG=osm-verkehrswende-keystatic-cms
+# For the static build, we only need the following variables.
+# They need to be part of `.github/workflows/deploy.yaml`
+# They are enforced by `astro.config.mjs` `env.schema``
 
-# Those variables belong into .github/workflows/deploy.yml
-# They are envored by `astro.config.mjs` `env.schema``
 # KEYSTATIC_STORAGE_KIND: "local"
 # ASTRO_ENV: "production"
 # ASTRO_OUTPUT_MODE: "static"

.env.example.local

@@ -1,9 +1,9 @@
 # Keystatic
 # Docs: https://keystatic.com/docs/github-mode
-KEYSTATIC_GITHUB_CLIENT_ID=     # empty
-KEYSTATIC_GITHUB_CLIENT_SECRET= # empty
-KEYSTATIC_SECRET=               # empty
-PUBLIC_KEYSTATIC_GITHUB_APP_SLUG=osm-verkehrswende-keystatic-cms
+KEYSTATIC_GITHUB_CLIENT_ID=     # Follow https://keystatic.com/docs/github-mode#setting-up-git-hub-mode
+KEYSTATIC_GITHUB_CLIENT_SECRET= # Dito
+KEYSTATIC_SECRET=               # Dito
+PUBLIC_KEYSTATIC_GITHUB_APP_SLUG=osm-verkehrswende-keystatic-cms # https://github.com/organizations/osmberlin/settings/apps/osm-verkehrswende-keystatic-cms
 KEYSTATIC_STORAGE_KIND=local
 
 ASTRO_ENV=development

.env.example.netlify

@@ -11,3 +11,5 @@ ASTRO_OUTPUT_MODE=server
 ASTRO_USE_NETLIFY_ADAPTER=true
 
 # Those variables need to be added to the Netlify site settings manually.
+# To create them, setup Keystatic for Github on local, following https://keystatic.com/docs/github-mode#setting-up-git-hub-mode
+# To edit the Github application, see https://github.com/Thinkmill/keystatic/pull/1358/files