add form element comment

src/mechanize/form.cr

@@ -8,7 +8,7 @@ require "./form/button"
 require "./form/select_list"
 require "./utils/element_matcher"
 
-# THis class represents the form tag of html.
+# This class represents the form tag of html.
 class Mechanize::Form
   include Mechanize::ElementMatcher
 
@@ -68,7 +68,7 @@ class Mechanize::Form
   elements_with "checkbox", "checkboxes"
   elements_with "button"
 
-  # Returns all fields of type Textarea
+  # Returns all fields of <input type="textarea">
   def textareas
     fields.select { |f| f.class == FormContent::Textarea }.map &.as(FormContent::Textarea)
   end

src/mechanize/form/field.cr

@@ -1,7 +1,14 @@
+# This class represents <input> elements in the form.
 class Mechanize::FormContent::Field
+
+  # returns field's 'value' attribute
   property value : String?
+  # returns field's 'name' attribute
   getter name : String
+  # returns field's 'type' attribute
   getter type : String
+  # returns field's 'value' attribute.
+  # value property is changeable, but this property stores raw value.
   getter raw_value : String?
   getter node : Node | Lexbor::Node
 
@@ -17,12 +24,12 @@ class Mechanize::FormContent::Field
     [@name, @value || ""]
   end
 
-  # returns DOM 'id' value
+  # returns field's 'id' value
   def dom_id
     node.fetch("id", "")
   end
 
-  # returns DOM 'class' value
+  # returns field's 'class' value
   def dom_class
     node.fetch("class", "")
   end

src/mechanize/form/hidden.cr

@@ -1,2 +1,3 @@
+# This class represents <input type="hidden">
 class Mechanize::FormContent::Hidden < Mechanize::FormContent::Field
 end

src/mechanize/form/text.cr

@@ -1,2 +1,3 @@
+# This class represents <input type="text">
 class Mechanize::FormContent::Text < Mechanize::FormContent::Field
 end

src/mechanize/form/textarea.cr

@@ -1,2 +1,3 @@
+# This class represents <input type="textarea">
 class Mechanize::FormContent::Textarea < Mechanize::FormContent::Field
 end