Apply Layout/LineLength rubocop rule

Note we're excluding a few files:

* Configuration files that weren't generated by us
* Migration files that weren't generated by us
* The Gemfile, since it includes an important comment that must be on
  the same line as the gem declaration
* The Budget::Stats class, since the heading statistics are a mess and
  having shorter lines would require a lot of refactoring

app/helpers/communities_helper.rb

@@ -8,7 +8,11 @@ module CommunitiesHelper
   end
 
   def community_description(community)
-    community.from_proposal? ? t("community.show.description.proposal") : t("community.show.description.investment")
+    if community.from_proposal?
+      t("community.show.description.proposal")
+    else
+      t("community.show.description.investment")
+    end
   end
 
   def author?(community, participant)
@@ -28,7 +32,11 @@ module CommunitiesHelper
   end
 
   def community_access_text(community)
-    community.from_proposal? ? t("community.sidebar.description.proposal") : t("community.sidebar.description.investment")
+    if community.from_proposal?
+      t("community.sidebar.description.proposal")
+    else
+      t("community.sidebar.description.investment")
+    end
   end
 
   def create_topic_link(community)