docs: update README.md [skip ci]

Author: allcontributors[bot]

README.md

@@ -4,7 +4,7 @@
 
 [![License](https://img.shields.io/badge/License-LGPL%203.0-blue.svg)](https://opensource.org/licenses/LGPL-3.0)
 ![CMake](https://github.com/fair-acc/gnuradio4/workflows/CMake/badge.svg) <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-7-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-8-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # GNU Radio 4.0 prototype
@@ -76,6 +76,9 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
       <td align="center" valign="top" width="14.28%"><a href="http://cukic.co"><img src="https://avatars.githubusercontent.com/u/90119?v=4" width="100px;" alt=""/><br /><sub><b>Ivan Čukić</b></sub></a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://mattkretz.github.io/"><img src="https://avatars.githubusercontent.com/u/3306474?v=4" width="100px;" alt=""/><br /><sub><b>Matthias Kretz</b></sub></a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/RalphSteinhagen"><img src="https://avatars.githubusercontent.com/u/46007894?v=4" width="100px;" alt=""/><br /><sub><b>Ralph J. Steinhagen</b></sub></a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://github.com/drslebedev"><img src="https://avatars.githubusercontent.com/u/25366186?v=4" width="100px;" alt=""/><br /><sub><b>drslebedev</b></sub></a></td>
+    </tr>
+    <tr>
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/mormj"><img src="https://avatars.githubusercontent.com/u/34754695?v=4" width="100px;" alt=""/><br /><sub><b>mormj</b></sub></a></td>
     </tr>
   </tbody>