HackStudio: Rename TextDocument => ProjectFile

TextDocument was not the right name, and got even more confusing with
the addition of GTextDocument in LibGUI.

DevTools/HackStudio/ProjectFile.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/NonnullRefPtr.h>
+#include <AK/RefCounted.h>
+#include <AK/String.h>
+#include <LibGUI/GTextDocument.h>
+
+class ProjectFile : public RefCounted<ProjectFile> {
+public:
+    static NonnullRefPtr<ProjectFile> construct_with_name(const String& name)
+    {
+        return adopt(*new ProjectFile(name));
+    }
+
+    const String& name() const { return m_name; }
+
+    const ByteBuffer& contents() const;
+
+    Vector<int> find(const StringView&) const;
+
+    const GTextDocument& document() const;
+
+private:
+    explicit ProjectFile(const String& name)
+        : m_name(name)
+    {
+    }
+
+    String m_name;
+    mutable ByteBuffer m_contents;
+    mutable RefPtr<GTextDocument> m_document;
+};