[real-world uses] Add some links

Author: marijnh

doc/realworld.html

@@ -82,8 +82,10 @@ <h2>CodeMirror real-world uses</h2>
       <li><a href="http://www.firepad.io">Firepad</a> (collaborative text editor)</li>
       <li><a href="https://gerritcodereview.com/">Gerrit</a>'s diff view and inline editor</li>
       <li><a href="https://github.com/maks/git-crx">Git Crx</a> (Chrome App for browsing local git repos)</li>
-      <li><a href="http://tour.golang.org">Go language tour</a></li>
       <li><a href="https://github.com/github/android">GitHub's Android app</a></li>
+      <li><a href="https://github.com/">Github</a>'s in-browser edit feature</li>
+      <li><a href="https://glitch.com/">Glitch</a> (community-driven app building)</li>
+      <li><a href="http://tour.golang.org">Go language tour</a></li>
       <li><a href="https://script.google.com/">Google Apps Script</a></li>
       <li><a href="http://web.uvic.ca/~siefkenj/graphit/graphit.html">Graphit</a> (function graphing)</li>
       <li><a href="https://hackmd.io">HackMD</a> (Realtime collaborative markdown notes on all platforms)</li>
@@ -135,6 +137,7 @@ <h2>CodeMirror real-world uses</h2>
       <li><a href="http://prose.io/">Prose.io</a> (github content editor)</li>
       <li><a href="https://pypi.python.org/pypi/PubliForge/">PubliForge</a> (online publishing system)</li>
       <li><a href="http://www.puzzlescript.net/">Puzzlescript</a> (puzzle game engine)</li>
+      <li><a href="https://chrome.google.com/webstore/detail/quantum/hmnlklahndgbhdoclhdnoafhafbhmnkm?hl=en-US">Quantum</a> (code editor for Chrome OS)</li>
       <li><a href="http://ql.io/">ql.io</a> (http API query helper)</li>
       <li><a href="http://qyapp.com">QiYun web app platform</a></li>
       <li><a href="http://ariya.ofilabs.com/2011/09/hybrid-webnative-desktop-codemirror.html">Qt+Webkit integration</a> (building a desktop CodeMirror app)</li>
@@ -145,6 +148,7 @@ <h2>CodeMirror real-world uses</h2>
       <li><a href="http://sagecell.sagemath.org">SageMathCell</a> (interactive mathematical software)</li>
       <li><a href="https://cloud.sagemath.com/">SageMathCloud</a> (interactive mathematical software environment)</li>
       <li><a href="https://chrome.google.com/webstore/detail/servephp/mnpikomdchjhkhbhmbboehfdjkobbfpo">ServePHP</a> (PHP code testing in Chrome dev tools)</li>
+      <li><a href="http://scala-lang.org/blog/2017/02/20/introducing-scastie.html">Scastie</a> (Scala playground)</li>
       <li><a href="https://www.shadertoy.com/">Shadertoy</a> (shader sharing)</li>
       <li><a href="http://www.sketchpatch.net/labs/livecodelabIntro.html">sketchPatch Livecodelab</a></li>
       <li><a href="http://www.skulpt.org/">Skulpt</a> (in-browser Python environment)</li>