[rubygems/rubygems] Replace "prior to" with "immediately after"

Currently, the instructions and placeholder contradict each other.

The commit that introduced this placeholder (42bc4715d920e836c8499883d)
makes it clear that the placeholder should be replaced AFTER publishing
(i.e. once the author successfully claims the gem name on Rubygems), so
the placeholder should match.

https://github.com/rubygems/rubygems/commit/23e2dea828

lib/bundler/templates/newgem/README.md.tt

@@ -6,15 +6,15 @@ Welcome to your new gem! In this directory, you'll find the files you need to be
 
 ## Installation
 
-TODO: Replace `UPDATE_WITH_YOUR_GEM_NAME_PRIOR_TO_RELEASE_TO_RUBYGEMS_ORG` with your gem name right after releasing it to RubyGems.org. Please do not do it earlier due to security reasons. Alternatively, replace this section with instructions to install your gem from git if you don't plan to release to RubyGems.org.
+TODO: Replace `UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG` with your gem name right after releasing it to RubyGems.org. Please do not do it earlier due to security reasons. Alternatively, replace this section with instructions to install your gem from git if you don't plan to release to RubyGems.org.
 
 Install the gem and add to the application's Gemfile by executing:
 
-    $ bundle add UPDATE_WITH_YOUR_GEM_NAME_PRIOR_TO_RELEASE_TO_RUBYGEMS_ORG
+    $ bundle add UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
 
 If bundler is not being used to manage dependencies, install the gem by executing:
 
-    $ gem install UPDATE_WITH_YOUR_GEM_NAME_PRIOR_TO_RELEASE_TO_RUBYGEMS_ORG
+    $ gem install UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
 
 ## Usage