Sign-in through the service worker (fixes: #20) (#25)

* Sign-in through the service worker (fixes: #20)

* Prettify

* Add MV2 listeners in background script

* Fix dependencies

* README correction

README.md

@@ -70,7 +70,7 @@ WORKDIR /opt/extension
 ENTRYPOINT ["sh"]
 ```
 
-### Developer workflow
+### Development workflow
 
 The table below outlines the sequence of steps that need to be followed in order to ship a change in the extension. The execution of some of these steps varies per browser/manifest version.
 
@@ -80,7 +80,7 @@ Note: the following console commands are to be executed from the root directory
 | # | Description | MV3 (Chromium) | MV2 (Firefox) |
 | - | - | - | - |
 | 0 | Install deps | `npm ci` | `npm ci && npm i -g web-ext` |
-| 1 | Spin up the DevServer. The server generates the `build` dir. | `npm run start` | `npm run start:v2` |
+| 1 | Spin up the DevServer. The server generates the `build` dir. | `npm run start` | `npm run start:mv2` |
 | 2 | Load the unpacked extension on the browser |  The `build` dir can be loaded as an unpacked extension through the browser's UI. See the relevant [Google Chrome guide](https://developer.chrome.com/docs/extensions/mv3/getstarted/development-basics/#load-unpacked). | `web-ext -s build run` |
 | 3 | Develop against the local browser instance on which the `build` dir is loaded | N/A | N/A |
 | 4 | Build productionised artefact | `npm run build` | `npm run build:mv2` |