Update 'ReadMe' with latest git push command syntax

Release note: No

Developer Comment:

Update EPPlus 'ReadMe' with latest git push command syntax


Change-Id: I95ba944fc44eda9758aa1f698a6b7cf989f6eff0
diff --git a/ReadMe_UpdatingEPPlus.txt b/ReadMe_UpdatingEPPlus.txt
index 14bf447..321c8ff 100644
--- a/ReadMe_UpdatingEPPlus.txt
+++ b/ReadMe_UpdatingEPPlus.txt
@@ -25,7 +25,7 @@
 1.	CD to folder GitHub\EPPlus.

 2.	Use Git to checkout branch AppSheet.

 3.	Change the appropriate source code files.

-4.	Checkin the changes to Git.

+4.	Checkin the changes to Git. Use the git push command: "git push origin HEAD:refs/for/main"

 5.	Build the EPPlus solution using Visual Studio 2017.

 6.	Copy the EPPlus.dll file produced by the build from folder Documents\GitHub\EPPlus\EPPlus\bin\Debug to folder Documents\GitHub\Jeenee\lib.

 7.	CD to folder Documents\GitHub\Jeenee.