Move the url opened when clicking the launch firefox button to config.

It was hardcoded in launch.js and was well suited for the debugger,
but other tools might want to see other default pages.

Author: nchevobbe

packages/devtools-launchpad/configs/development.json

@@ -5,6 +5,7 @@
   "favicon": "assets/launchpad-favicon.png",
   "theme": "light",
   "dir": "ltr",
+  "defaultURL": "https://devtools-html.github.io/debugger-examples/",
   "logging": {
     "client": false,
     "firefoxProxy": false,

packages/devtools-launchpad/src/server/launch.js

@@ -12,7 +12,7 @@ const {
 
 function handleLaunchRequest(req, res) {
   const browser = req.body.browser;
-  const location = "https://devtools-html.github.io/debugger-examples/";
+  const location = getValue("defaultURL");
 
   process.env.PATH += `:${__dirname}`;
   if (browser == "Firefox") {