chore: rename default branch to main

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-    branches: [master]
+    branches: [main]
 
 permissions:
   contents: read
@@ -48,7 +48,7 @@ jobs:
       - name: Build
         run: npm run build
 
-      # `on.push` is restricted to master, so this only ever runs for master.
+      # `on.push` is restricted to main, so this only ever runs for main.
       # Pull request runs stop after the build above and never publish.
       - name: Upload Pages artifact
         if: github.event_name == 'push'

README.md

@@ -80,7 +80,7 @@ npm run build
 
 Creates a production bundle for the app.
 
-Deployment is automatic: every push to `master` builds the site and publishes it
+Deployment is automatic: every push to `main` builds the site and publishes it
 to GitHub Pages via `.github/workflows/ci.yml`. Pull requests build but never
 publish. There is no manual deploy step.