Add a section about preparing the phone for development

Development_Environment.rst

@@ -14,4 +14,5 @@ itself, a development kit or with an emulator that runs on a workstation.
    Development_Environment/Requirements.rst
    Development_Environment/Boards.rst
    Development_Environment/Boards/emulators.rst
+   Development_Environment/Phone.rst
    Development_Environment/Workstation.rst

Development_Environment/Phone.rst

+.. _phone_setup:
+
+Setting up the Phone
+====================
+
+.. note:: This section is subject to updates and revisions prior to the phone's
+          release.
+
+This section should describe the steps needed to set up the Librem 5 phone for
+application development. This includes any preparations related to the
+hardware, such as connecting USB cables and ensuring that the phone is powered.
+It should also describe the software that needs to be installed on the phone,
+such as packages that will enable or assist software development.