Merge pull request #16408 from aditya-kapoor/add-doc-ERB-escape

[ci skip] add note about the ERB escape in generator docs

guides/source/generators.md

@@ -8,6 +8,7 @@ After reading this guide, you will know:
 * How to see which generators are available in your application.
 * How to create a generator using templates.
 * How Rails searches for generators before invoking them.
+* How Rails internally generates Rails code from the templates.
 * How to customize your scaffold by creating new generators.
 * How to customize your scaffold by changing generator templates.
 * How to use fallbacks to avoid overwriting a huge set of generators.
@@ -340,6 +341,20 @@ end
 
 If you generate another resource, you can see that we get exactly the same result! This is useful if you want to customize your scaffold templates and/or layout by just creating `edit.html.erb`, `index.html.erb` and so on inside `lib/templates/erb/scaffold`.
 
+Many scaffold templates in Rails are written in ERB tags which needs to be escaped, so that the output is a valid ERB code, that can be used correctly in Rails app.
+
+The following code in one of the generator file,
+
+```ruby
+<%%= stylesheet_include_tag :application %>
+```
+
+when passed through the generator, would generate the following output.
+
+```ruby
+<%= stylesheet_include_tag :application %>
+```
+
 Adding Generators Fallbacks
 ---------------------------