Apply style guide: persistence feature

wiki/src/contribute/how/documentation/style_guide.mdwn

@@ -57,8 +57,8 @@
   To refer to the features available in the configuration of the
   *persistent storage*.
 
-  - *For example*: when the <span class="guilabel">Additional
-    Software</span> persistence feature is activated.
+  - *For example*: when the [[<span class="guilabel">Additional
+    Software</span> persistence feature|doc/first_steps/persistence/configure#additional_software]] is activated.
 
   The word *persistence* can be omitted if it is redundant from the context
   (for example on [[doc/first_steps/persistence/configure]]).

wiki/src/doc/first_steps/additional_software.mdwn

@@ -125,8 +125,9 @@ Additional configuration
 ------------------------
 
 Some packages require additional configuration to work. To keep the
-configuration across Tails sessions, you can use the [[dotfiles
-|first_steps/persistence/configure#dotfiles]] feature.
+configuration across Tails sessions, you can use the [[<span
+class="guilabel">Dotfiles</span> persistence
+feature|first_steps/persistence/configure#dotfiles]].
 
 Checking your list of additional software
 =========================================