Fix readme and change release trigger (#2)

Author: billytrend

.ci/publish.yml

@@ -1,5 +1,7 @@
 trigger:
-  - master
+  tags:
+    include:
+      - v*
 
 pr: none
 
@@ -18,5 +20,5 @@ stages:
               containerRegistry: "github-nginx-cache docker"
               repository: "azuredevx/github-nginx-cache"
               tags: |
-                $(Build.BuildNumber)
+                $(Build.SourceBranchName)
                 latest

README.md

@@ -8,7 +8,7 @@ Here is an example how rate-limiting is mitigated for unauthenticated requests a
 
 ### Quick Start
 
-    docker run -d -p 8000:80 azure-devex/github-nginx-cache
+    docker run -d -p 8000:80 azuredevex/github-nginx-cache
     curl localhost:8000/api/repos/azure/github-nginx-cache
 
 The github domains are mapped as follows: