Remove redundant blank comment lines

src/ameba/ast/branch.cr

@@ -11,7 +11,6 @@ module Ameba::AST
   #   do_something a # --> Branch D
   # end
   # ```
-  #
   class Branch
     # The actual branch node.
     getter node : Crystal::ASTNode

src/ameba/ast/visitors/node_visitor.cr

@@ -35,7 +35,6 @@ module Ameba::AST
   # ```
   # visitor = Ameba::AST::NodeVisitor.new(rule, source)
   # ```
-  #
   class NodeVisitor < BaseVisitor
     @skip : Array(Crystal::ASTNode.class)?
 

src/ameba/tokenizer.cr

@@ -10,7 +10,6 @@ module Ameba
   #   puts token
   # end
   # ```
-  #
   class Tokenizer
     # Instantiates Tokenizer using a `source`.
     #