Add a firefox add-on

modules/microsite/src/main/tut/doc/tools.md

@@ -105,3 +105,83 @@ Example:
 ``` bash
 ./ds.sh ~/Downloads/*.pdf
 ```
+
+
+## Webextension for Docspell
+
+Idea: Inside the browser click on a PDF and send it to docspell. It is
+downloaded in the context of your current page. Then handed to an
+application that pushes it to docspell. There is a browser add-on
+implementing this in `tools/webextension`. This add-on only works with
+firefox.
+
+### Install
+
+This is a bit complicated, since you need to install external tools
+and the web extension. Both work together.
+
+#### Install `ds.sh`
+
+First install the `ds.sh` tool somewhere, maybe `/usr/local/bin` as
+described above.
+
+
+#### Install the native part
+
+Then install the "native" part of the web extension:
+
+Copy or symlink the `native.py` script into some known location. For
+example:
+
+``` bash
+ln -s ~/docspell-checkout/tools/webextension/native/native.py /usr/local/share/docspell/native.py
+```
+
+Then copy the `app_manifest.json` to
+`$HOME/.mozilla/native-messaging-hosts/docspell.json`. For example:
+
+``` bash
+cp ~/docspell-checkout/tools/webextension/native/app_manifest.json  ~/.mozilla/native-messaging-hosts/docspell.json
+```
+
+See
+[here](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Native_manifests#Manifest_location)
+for details.
+
+And you might want to modify this json file, so the path to the
+`native.py` script is correct (it must be absolute).
+
+If the `ds.sh` script is in your `$PATH`, then this should
+work. Otherwise, edit the `native.py` script and change the path to
+the tool. Or create a file `$HOME/.config/docspell/ds.cmd` whose
+content is the path to the `ds.sh` script.
+
+
+#### Install the extension
+
+An extension file can be build using the `make-xpi.sh` script. But
+installing it in "standard" firefox won't work, because [Mozilla
+requires extensions to be signed by
+them](https://wiki.mozilla.org/Add-ons/Extension_Signing). This means
+creating an account and going through some process…. So here are two
+alternatives:
+
+1. Open firefox and type `about:debugging` in the addressbar. Then
+   click on *'Load Temporary Add-on...'* and select the
+   `manifest.json` file. The extension is now installed. The downside
+   is, that the extension will be removed once firefox is closed.
+2. Use Firefox ESR, which allows to install Add-ons not signed by
+   Mozilla. But it has to be configured: Open firefox and type
+   `about:config` in the address bar. Search for key
+   `xpinstall.signatures.required` and set it to `false`. This is
+   described on the last paragraph on [this
+   page](https://support.mozilla.org/en-US/kb/add-on-signing-in-firefox).
+
+When you right click on a file link, there should be a context menu
+entry *'Docspell Upload Helper'*. The add-on will download this file
+using the browser and then send the file path to the `native.py`
+script. This script will in turn call `ds.sh` which finally uploads it
+to your configured URLs.
+
+Open the Add-ons page (`Ctrl`+`Shift`+`A`), the new add-on should be
+there.