Update README.md - fixed minor typo

Minor typo, `healper` --> `helper`

README.md

@@ -778,7 +778,7 @@ algorithms, knowledgebase and AI technology.
 * [Clip Blast](http://www.clipblast.com)
 * [DailyMotion](http://www.dailymotion.com)
 * [Deturl](http://deturl.com) - Download a YouTube video from any web page.
-* [DownloadHealper](http://www.downloadhelper.net) - Download any video from any websites, it just works!
+* [DownloadHelper](http://www.downloadhelper.net) - Download any video from any websites, it just works!
 * [Earthcam](http://www.earthcam.com) - EarthCam is the leading network of live streaming webcams for tourism and entertainment.
 * [Filmot](https://filmot.com/) - Search within YouTube subtitles. Indexing over 573 million captions across 528 million videos and 45 million channels.
 * [Find YouTube Video](https://findyoutubevideo.thetechrobo.ca/) - Searches currently 5 YouTube archives for specific videos by ID, which is really useful for finding deleted or private YouTube videos.