Add personal contribution note by Tinu280

Added a personal contribution note to the README.

Author: Tinu280

README.md

@@ -254,3 +254,5 @@ also included in our repository in the `COPYING.LESSER` file.
 The go-ethereum binaries (i.e. all code inside of the `cmd` directory) are licensed under the
 [GNU General Public License v3.0](https://www.gnu.org/licenses/gpl-3.0.en.html), also
 included in our repository in the `COPYING` file.
+
+My first contribution test by Tinu280