Improve chrome:// URL docs

CONTRIBUTING.asciidoc

@@ -555,22 +555,25 @@ If you want to rebuild the website, run `./scripts/asciidoc2html.py --website <o
 Chrome URLs
 ~~~~~~~~~~~
 
-Qutebrowser supports several chrome urls.  A short list of them can be found here:
-
-chrome://appcache-internals/
-chrome://blob-internals/
-chrome://gpu/
-chrome://histograms/
-chrome://indexeddb-internals/
-chrome://media-internals/
-chrome://network-errors/
-chrome://serviceworker-internals/
-chrome://webrtc-internals/
-chrome://crash/
-chrome://kill/
-chrome://gpucrash/ 
-chrome://gpuhang/
+With the QtWebEngine backend, qutebrowser supports several chrome:// urls which
+can be useful for debugging:
 
+- chrome://appcache-internals/
+- chrome://blob-internals/
+- chrome://gpu/
+- chrome://histograms/
+- chrome://indexeddb-internals/
+- chrome://media-internals/
+- chrome://network-errors/
+- chrome://serviceworker-internals/
+- chrome://webrtc-internals/
+- chrome://crash/ (crashes the current renderer process!)
+- chrome://kill/ (kills the current renderer process!)
+- chrome://gpucrash/ (crashes qutebrowser!)
+- chrome://gpuhang/ (hangs qutebrowser!)
+- chrome://gpuclean/ (crashes the current renderer process!)
+- chrome://ppapiflashcrash/
+- chrome://ppapiflashhang/
 
 Style conventions
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