Add copyright

Author: hamnarauf

doc/stp/MSTP_HLD.md

@@ -5,6 +5,8 @@
 
 ## Revision History
 
+[© xFlow Research Inc](https://xflowresearch.com/) 
+
 |Revision No.|Description|Author|Date|
 | :- | :- | :- | :- |
 |0.1|Intial Design|[Hamna Rauf](https://github.com/hamnarauf), [Muhammad Danish](https://github.com/mdanish-kh), [Rida Hanif](github.com/ridahanif96), [Hafiz Mati ur Rehman](https://github.com/Mati86)  & [Arsalan Ahmad](https://github.com/ahmadarsalan/)|March 20, 2023|