Tag `@doc` scenarios that rely on the documentation.

Will-fix: #10706

features/checks.feature

@@ -30,6 +30,7 @@ Feature: Various checks
     Given I have started Tails from DVD without network and logged in
     Then the shipped Debian repository key will be valid for the next 3 months
 
+  @doc
   Scenario: The "Report an Error" launcher will open the support documentation
     Given I have started Tails from DVD without network and logged in
     And the network is plugged

features/localization.feature

@@ -4,6 +4,7 @@ Feature: Localization
   I want Tails to be localized in my native language
   And various Tails features should still work
 
+  @doc
   Scenario: The Report an Error launcher will open the support documentation in supported non-English locales
     Given I have started Tails from DVD without network and stopped at Tails Greeter's login screen
     And the network is plugged

features/po.feature

@@ -3,6 +3,7 @@ Feature: check PO files
   As a Tails developer, when I build Tails, I want to make sure
   the PO files in use are correct.
 
+  @doc
   Scenario: check all PO files
     Given I am in the Git branch being tested
     Then all the PO files should be correct

features/torified_browsing.feature

@@ -94,6 +94,7 @@ Feature: Browsing the web using the Tor Browser
     When I open the address "file:///tmp/synaptic.html" in the Tor Browser
     Then I do not see "TorBrowserSynapticManual.png" after at most 5 seconds
 
+  @doc
   Scenario: The "Tails documentation" link on the Desktop works
     Given I have started Tails from DVD and logged in and the network is connected
     When I double-click on the "Tails documentation" link on the Desktop