Improve documentation theme.

src/ftxui/component/collapsible.cpp

@@ -28,7 +28,7 @@ namespace ftxui {
 ///
 /// ▼ Show details
 /// <details component>
-///  ```
+/// ```
 // NOLINTNEXTLINE
 Component Collapsible(ConstStringRef label, Component child, Ref<bool> show) {
   class Impl : public ComponentBase {

src/ftxui/component/event.cpp

@@ -74,7 +74,7 @@ Event Event::CursorShape(std::string input, int shape) {
 
 /// @brief An custom event whose meaning is defined by the user of the library.
 /// @param input An arbitrary sequence of character defined by the developer.
-/// @ingroup component.
+/// @ingroup component
 // static
 Event Event::Special(std::string input) {
   Event event;

src/ftxui/component/hoverable.cpp

@@ -159,7 +159,7 @@ ComponentDecorator Hoverable(bool* hover) {
 /// button |= Hoverable(
 ///   [&]{ on_enter_cnt++; },
 ///   [&]{ on_leave_cnt++; }
-//  );
+/// );
 /// ```
 // NOLINTNEXTLINE
 ComponentDecorator Hoverable(std::function<void()> on_enter,
@@ -182,7 +182,7 @@ ComponentDecorator Hoverable(std::function<void()> on_enter,
 /// auto button = Button("exit", screen.ExitLoopClosure());
 /// bool hovered = false;
 /// auto button_hoverable = Hoverable(button,
-//                                    [&](bool hover) { hovered = hover;});
+///                                   [&](bool hover) { hovered = hover;});
 /// ```
 // NOLINTNEXTLINE
 Component Hoverable(Component component, std::function<void(bool)> on_change) {

src/ftxui/component/input.cpp

@@ -603,6 +603,7 @@ Component Input(StringRef content, InputOption option) {
 
 /// @brief An input box for editing text.
 /// @param content The editable content.
+/// @param placeholder The placeholder text.
 /// @param option Additional optional parameters.
 /// @ingroup component
 /// @see InputBase