Trigger build per projectName path

Signed-off-by: Mathieu Benoit <mabenoit@microsoft.com>

azure-build-pipeline.yml

@@ -7,6 +7,11 @@ variables:
   imageName: '$(projectName)'
   # define 4 more variables: projectName, registryName, registryLogin and registryPassword in the build pipeline in UI
 
+trigger:
+  batch: true
+  paths:
+    include:
+    - $(projectName)/*
 
 steps:
 - bash: docker build -f $(system.defaultWorkingDirectory)/$(projectName)/Dockerfile -t $(registryServerName)/$(imageName):$(build.buildId) -t $(registryServerName)/$(imageName):latest $(system.defaultWorkingDirectory)/$(projectName)