feat: add markdown support for user notes (#6490)

Reviewed-by: pajlada <rasmus.karlsson@pajlada.com>
Reviewed-by: Nerixyz <nerixdev@outlook.de>

src/widgets/MarkdownLabel.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "widgets/Label.hpp"
+
+class QTextDocument;
+
+namespace chatterino {
+
+/// @brief A Label that supports rendering markdown text
+///
+/// MarkdownLabel inherits from Label and adds markdown rendering capabilities.
+/// It automatically handles markdown document creation and rendering.
+class MarkdownLabel : public Label
+{
+public:
+    explicit MarkdownLabel(BaseWidget *parent, QString text,
+                           FontStyle style = FontStyle::UiMedium);
+
+    void setText(const QString &text);
+
+protected:
+    void paintEvent(QPaintEvent * /*event*/) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+
+private:
+    void updateSize() override;
+
+    QTextDocument *markdownDocument;
+};
+
+}  // namespace chatterino