📝 Update doc and pull request body

Author: wei

README.md

@@ -54,6 +54,9 @@ Incorporate new changes as they happen, not in 6 months.
 
 Trusted by [![Repository Count](https://pull.git.ci/badge/managing?plain&style=flat)](https://probot.github.io/apps/pull/) repositories, triggered [![Triggered #](https://pull.git.ci/badge/triggered?plain&style=flat)](https://github.com/issues?q=author%3Aapp%2Fpull) times.
 
+Want to support this open source service? [Please star it : )](https://github.com/wei/pull)
+
+
 ## Features
 
  - Ensure forks are updated.

lib/helper.js

@@ -6,4 +6,5 @@ exports.getPRTitle = (ref, upstream) =>
 exports.getPRBody = (repoPath, prNumber) =>
   (prNumber
     ? `See [Commits](/${repoPath}/pull/${prNumber}/commits) and [Changes](/${repoPath}/pull/${prNumber}/files) for more details.\n\n-----\nCreated by [<img src="https://prod.download/pull-18h-svg" valign="bottom"/> **pull[bot]**](https://github.com/wei/pull)`
-    : `See Commits and Changes for more details.\n\n-----\nCreated by [<img src="https://prod.download/pull-18h-svg" valign="bottom"/> **pull[bot]**](https://github.com/wei/pull)`)
+    : `See Commits and Changes for more details.\n\n-----\nCreated by [<img src="https://prod.download/pull-18h-svg" valign="bottom"/> **pull[bot]**](https://github.com/wei/pull)`) +
+  `. Want to support this open source service? [Please star it : )](https://github.com/wei/pull)`