Changelog improvements [ci skip]

actionpack/CHANGELOG.md

-*   Fix generating a path for engine inside a resources block (#8533)
+*   Fix generating a path for engine inside a resources block.
+
+    Fixes #8533.
 
     *Piotr Sarnacki*
 
-*   Add Mime::Type.register "text/vcard", :vcf to the default list of mime types
+*   Add `Mime::Type.register "text/vcard", :vcf` to the default list of mime types.
 
     *DHH*
 
@@ -26,7 +28,7 @@
     The request variant is a specialization of the request format, like `:tablet`,
     `:phone`, or `:desktop`.
 
-    You can set the variant in a before_action:
+    You can set the variant in a `before_action`:
 
         request.variant = :tablet if request.user_agent =~ /iPad/
 
@@ -85,7 +87,7 @@
 
 *   Add `session#fetch` method
 
-    fetch behaves like [Hash#fetch](http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch).  
+    fetch behaves like [Hash#fetch](http://www.ruby-doc.org/core-1.9.3/Hash.html#method-i-fetch).
     It returns a value from the hash for the given key.
     If the key can’t be found, there are several options:
 

activerecord/CHANGELOG.md

 *   Use the right column to type cast grouped calculations with custom expressions.
 
-    Fixes: #13230
+    Fixes #13230.
 
     Example:
 
-            # Before
-            Account.group(:firm_name).sum('0.01 * credit_limit')
-            # => { '37signals' => '0.5' }
+        # Before
+        Account.group(:firm_name).sum('0.01 * credit_limit')
+        # => { '37signals' => '0.5' }
 
-            # After
-            Account.group(:firm_name).sum('0.01 * credit_limit')
-            # => { '37signals' => 0.5 }
+        # After
+        Account.group(:firm_name).sum('0.01 * credit_limit')
+        # => { '37signals' => 0.5 }
 
     *Paul Nikitochkin*
 

activesupport/CHANGELOG.md

-*   Fix file descriptor being leaked on each call to `Kernel.silence_stream`
+*   Fix file descriptor being leaked on each call to `Kernel.silence_stream`.
 
     *Mario Visic*