fix: enable the build information under Netlify environment

packages/docs/modules/banner/module.ts

@@ -3,12 +3,15 @@ import { resolve } from 'pathe'
 import packageJson from '../../../ui/package.json'
 
 // This is an in-place way to figure out commit hash,
-//  but as we use railway, we have to use their variables.
+//  but as we use Netlify, we have to use their variables.
 // import { execSync } from 'child_process'
 // const getLastCommitHash = () => {
 //   return execSync('git rev-parse HEAD').toString().trim()
 // }
 
+// Netlify has several Git metadata read-only variables: COMMIT_REF, BRANCH, etc.
+// see https://docs.netlify.com/configure-builds/environment-variables/#git-metadata for more details
+
 /** Module used to add current file path to page-config */
 export default defineNuxtModule<any>({
   meta: {
@@ -20,9 +23,9 @@ export default defineNuxtModule<any>({
     exclude: './page-config/**/*.{.vue,.md}',
   },
 
-  setup(options) {
-    if (!process.env.RAILWAY_GIT_COMMIT_SHA) {
-      console.warn("Banner module is disabled because RAILWAY_GIT_COMMIT_SHA is not present in .env")
+  setup() {
+    if (!process.env.COMMIT_REF) {
+      console.warn('Banner module is disabled because COMMIT_REF is not present in .env')
       return
     }
 
@@ -32,8 +35,8 @@ export default defineNuxtModule<any>({
       options: {
         VERSION: packageJson.version,
         DATE: new Date().toLocaleString(),
-        COMMIT: process.env.RAILWAY_GIT_COMMIT_SHA.slice(0,7), // same as github commit shortcut
-        BRANCH: process.env.RAILWAY_GIT_BRANCH,
+        COMMIT: process.env.COMMIT_REF.slice(0,7), // same as GitHub commit shortcut
+        BRANCH: process.env.BRANCH,
       }
     })
   }