chore: update Pipfile

docs/devs/extensions.md

@@ -22,3 +22,22 @@ Going over the example extension's structure:
 * migrations.py: Create database tables for your plugin. They'll be created when you run `pipenv run flask migrate`.
 
 ... This document is a work-in-progress. Send pull requests if you get stuck, so others don't.
+
+
+Adding new dependencies
+-----------------------
+
+If for some reason your extensions needs a new python package to work, you can add a new package using Pipenv:
+
+```sh
+$ pipenv install new_package_name
+```
+
+This will create a new entry in the `Pipenv` file.
+**But we need an extra step to make sure LNbits doesn't break in production.**
+All tests and deployments should run against the `requirements.txt` file so every time a new package is added
+it is necessary to run the Pipenv `lock` command and manually update the requirements file:
+
+```sh
+$ pipenv lock -r
+```