Added comments (#369 #370)

imgui.cpp

@@ -7217,6 +7217,7 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
         if (g.IO.InputCharacters[0])
         {
             // Process text input (before we check for Return because using some IME will effectively send a Return?)
+            // We ignore CTRL inputs, but need to allow CTRL+ALT as some keyboards (e.g. German) use AltGR - which is Alt+Ctrl - to input certain characters.
             if (!(is_ctrl_down && !is_alt_down) && is_editable)
             {
                 for (int n = 0; n < IM_ARRAYSIZE(g.IO.InputCharacters) && g.IO.InputCharacters[n]; n++)