fix slingcode syntax

README.md

@@ -1368,7 +1368,7 @@ _See [Ticketing](#ticketing)_
 - [Regexr](http://regexr.com/) - RegExr is a HTML/JS based tool for creating, testing, and learning about Regular Expressions. ([Source Code](https://github.com/gskinner/regexr)) `MIT` `Nodejs`
 - [RequestBin](https://github.com/Runscope/requestbin) - Inspect HTTP requests. Debug webhooks. `MIT` `python`
 - [RStudio Server](https://www.rstudio.com/products/rstudio/#Server) - Web browser based IDE for R. ([Source Code](https://github.com/rstudio/rstudio)) `AGPL-3.0` `Java/C++`
-- [Slingcode](https://slingcode.net/) - Web app IDE and computing platform in a single static HTML file. ([Demo](https://slingcode.net/slingcode.html) [Source Code](https://github.com/chr15m/slingcode/)) `MIT` `HTML`
+- [Slingcode](https://slingcode.net/) - Web app IDE and computing platform in a single static HTML file. ([Demo](https://slingcode.net/slingcode.html), [Source Code](https://github.com/chr15m/slingcode/)) `MIT` `HTML`
 - [sourcegraph](https://sourcegraph.com) - Sourcegraph is a fast, open-source, fully-featured code search and navigation engine written in Go. ([Source Code](https://github.com/sourcegraph/sourcegraph)) `Apache-2.0` `Go`
 - [Wakapi](https://github.com/n1try/wakapi) - Tracking tool for coding statistics, compatible with WakaTime. `GPL-3.0` `Go`