Prefill issue content for reporting package initialization errors

lib/package-initialization-error-component.js

@@ -1,4 +1,5 @@
 const etch = require('etch')
+const {URL} = require('url')
 const $ = etch.dom
 
 module.exports =
@@ -16,7 +17,6 @@ class PackageInitializationErrorComponent {
   render () {
     return $.div({className: 'PackageInitializationErrorComponent'},
       $.h3(null, 'Teletype initialization failed'),
-      $.p(null, 'Error: ' + this.props.initializationError.message),
       $.p(null, 'Make sure your internet connection is working and restart the package.'),
       $.div(null,
         $.button(
@@ -31,12 +31,27 @@ class PackageInitializationErrorComponent {
       ),
       $.p(null,
         'If the problem persists, visit ',
-        $.a({href: 'https://github.com/atom/teletype/issues/new', className: 'text-info'}, 'atom/teletype'),
+        $.a({href: this.getIssueURL(), className: 'text-info'}, 'atom/teletype'),
         ' and open an issue.'
       )
     )
   }
 
+  getIssueURL () {
+    const {initializationError} = this.props
+
+    const url = new URL('https://github.com/atom/teletype/issues/new')
+    url.searchParams.append('title', 'Package Initialization Error')
+    url.searchParams.append('body',
+      '### Diagnostics\n\n' +
+      '```\n' +
+      initializationError.diagnosticMessage + '\n' +
+      '```\n'
+    )
+
+    return url.href
+  }
+
   async restartTeletype () {
     const {packageManager} = this.props
     await packageManager.deactivatePackage('teletype')