- Add lens:// protocol handling with a routing mechanism

- document the methods in an extension guide

- remove handlers when an extension is deactivated or removed

- make sure that the found extension when routing a request is currently enabled (as a backup)

- added documentation about the above behaviour to the guide

- tweaked the naming convention so that it is clearer that the router uses extension names as not IDs (which currently are folder paths)

- Convert the extension API to use an array for registering handlers

- switch design to execute both main and renderer handlers simultaneously, without any overlap checking

- change open to be a dev dep

- improve docs, export types for extensions, skip integration tests

- switch to event emitting renderer being ready

- Add logging and fix renderer:loaded send to main
Signed-off-by: Sebastian Malton <sebastian@malton.name>