Add Transmission bittorrent client/seedbox

+ fix horizontal line markdown formatting

README.md

@@ -8,7 +8,7 @@ This is a list of [Free](https://en.wikipedia.org/wiki/Free_software) Software [
 
 See [Contributing](.github/CONTRIBUTING.md).
 
-=================
+--------------------
 
   - [Analytics](#analytics)
   - [Automation](#automation)
@@ -589,6 +589,7 @@ See https://github.com/n1trux/awesome-sysadmin#distributed-filesystems
   * [peerflix-server](https://github.com/asapach/peerflix-server) - Downloads torrent files and provides a direct link download or a direct link stream. `MIT` `Nodejs`
   * [rartracker](https://github.com/swetorrentking/rartracker) - Complete private bittorrent tracker. `WTFPL` `PHP`
   * [Reep](https://reep.io) - In-browser peer-to-peer file transfer and streaming made easy. ([Source Code](https://github.com/KodeKraftwerk/reepio)) `GPLv2` `Nodejs`
+  * [Transmission](https://transmissionbt.com/) - A fast, easy, Free Bittorrent client. ([Source Code](https://github.com/transmission/transmission)) `GPLv3` `C`
 
 #### Single-click/drag-n-drop upload