HackStudio: Move everything into the HackStudio namespace

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/c0462c65cfb

DevTools/HackStudio/ProjectFile.cpp

@@ -28,6 +28,8 @@
 #include <LibCore/File.h>
 #include <string.h>
 
+namespace HackStudio {
+
 ProjectFile::ProjectFile(const String& name)
     : m_name(name)
 {
@@ -45,3 +47,5 @@ const GUI::TextDocument& ProjectFile::document() const
     }
     return *m_document;
 }
+
+}