Follow-up to #16097 [ci skip]

Even if this is not exactly the same, let's add a new-line character
instead of two spaces. While it's specified in the Markdown specs that
adding spaces at the end of the line creates a break-line tag, this is
a brittle approach as people may remove them saving the file on certain
editors.

CONTRIBUTING.md

@@ -12,5 +12,6 @@ Ruby on Rails is a volunteer effort. We encourage you to pitch in. [Join the tea
 
 * If you have a change or new feature in mind, please [suggest it on the rubyonrails-core mailing list](https://groups.google.com/forum/?fromgroups#!forum/rubyonrails-core) and start writing code.
 
-Thanks! :heart: :heart: :heart:  
+Thanks! :heart: :heart: :heart:
+
 Rails Team

guides/source/asset_pipeline.md

@@ -124,19 +124,22 @@ with a built-in helper. In the source the generated code looked like this:
 The query string strategy has several disadvantages:
 
 1. **Not all caches will reliably cache content where the filename only differs by
-query parameters**  
+query parameters**
+
     [Steve Souders recommends](http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/),
  "...avoiding a querystring for cacheable resources". He found that in this
 case 5-20% of requests will not be cached. Query strings in particular do not
 work at all with some CDNs for cache invalidation.
 
-2. **The file name can change between nodes in multi-server environments.**  
+2. **The file name can change between nodes in multi-server environments.**
+
     The default query string in Rails 2.x is based on the modification time of
 the files. When assets are deployed to a cluster, there is no guarantee that the
 timestamps will be the same, resulting in different values being used depending
 on which server handles the request.
 
-3. **Too much cache invalidation**  
+3. **Too much cache invalidation**
+
     When static assets are deployed with each new release of code, the mtime
 (time of last modification) of _all_ these files changes, forcing all remote
 clients to fetch them again, even when the content of those assets has not changed.