github-merge-pr: add generic enough instruction on how to use the script

Add generic enough instruction on how to use the github-merge-pr script.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

diff --git a/github-merge-pr.sh b/github-merge-pr.sh
index 6d0dbe558aeb9178124b01b2e1c97756df4f01e8..e22f3df4155ee48c0d5e38338fc57f7342505316 100755 (executable)
--- a/github-merge-pr.sh
+++ b/github-merge-pr.sh
@@ -1,5 +1,13 @@
 #!/bin/bash
 
+# How to setup the repository to make this correctly work
+# 1. Clone repo and make sure you can correctly push to that
+#    (example with openwrt main repo you need to use ssh remote url)
+# 2. Make sure you can correctly push and force push to the github
+#    repository
+#
+# Usage: github-merge-pr.sh PR_NUMBER BRANCH
+
 # Github repository, just the name/repo part, no .git suffix, no base url!
 REPO="openwrt/openwrt"