modified the guidelines

Author: SidharthBansal

doc/devel/release_guide.rst

@@ -114,7 +114,7 @@ Similarly for the "API changes",
  1. copy the current api changes to a file is :file:`doc/api/prev_api_changes`
  2. merge all of the files in the most recent :file:`doc/api/api_changes_X.Y`
     into :file:`doc//whats_new.rst`
- 3. comment out the next API changes at the top.
+ 3. comment out the most recent API changes at the top.
 
 In both cases step 3 will have to be un-done right after the release.