Update workflow trigger, README

.github/workflows/build-and-push.yml

@@ -3,6 +3,8 @@ name: Build and Push Docker Images
 on:
   push:
     branches: [ main ]
+    paths:
+      - 'build/VERSION'
   
   release:
     types: [ published ]
@@ -21,7 +23,6 @@ env:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
-    if: contains(github.event.head_commit.message, 'build/')
     permissions:
       contents: write
       packages: write