Don't recommend using certbot-auto. (#8222)

Fixes https://github.com/certbot/certbot/issues/8165.

I moved `prerequisites` up to the "Running a local copy of the client" `contributing.html#prerequisites` still links to information about installing Cerbot's dependencies.

I left all certbot-auto documentation that wasn't explicitly encouraging its use. I think we can rip that out once the script is deprecated.

certbot/docs/contributing.rst

@@ -18,6 +18,7 @@ Windows, you'll need to set up a (virtual) machine running an OS such as Linux
 and continue with these instructions on that UNIX-like OS.
 
 .. _local copy:
+.. _prerequisites:
 
 Running a local copy of the client
 ----------------------------------
@@ -578,33 +579,3 @@ effect. To do this, run::
 Now running the check for linting errors described above is as easy as::
 
   tox -e lint
-
-.. _prerequisites:
-
-Notes on OS dependencies
-========================
-
-OS-level dependencies can be installed like so:
-
-.. code-block:: shell
-
-   ./certbot-auto --debug --os-packages-only
-
-In general...
-
-* ``sudo`` is required as a suggested way of running privileged process
-* `Python`_ 2.7 or 3.6+ is required
-* `Augeas`_ is required for the Python bindings
-* ``virtualenv`` is used for managing other Python library dependencies
-
-.. _Python: https://wiki.python.org/moin/BeginnersGuide/Download
-.. _Augeas: http://augeas.net/
-.. _Virtualenv: https://virtualenv.pypa.io
-
-
-FreeBSD
--------
-
-FreeBSD by default uses ``tcsh``. In order to activate virtualenv (see
-above), you will need a compatible shell, e.g. ``pkg install bash &&
-bash``.

certbot/docs/install.rst

@@ -18,7 +18,7 @@ Certbot is packaged for many common operating systems and web servers. Check whe
 certbot.eff.org_, where you will also find the correct installation instructions for
 your system.
 
-.. Note:: Unless you have very specific requirements, we kindly suggest that you use the Certbot packages provided by your package manager (see certbot.eff.org_). If such packages are not available, we recommend using ``certbot-auto``, which automates the process of installing Certbot on your system.
+.. Note:: Unless you have very specific requirements, we kindly suggest that you use the installation instructions for your system found at certbot.eff.org_.
 
 .. _certbot.eff.org: https://certbot.eff.org
 
@@ -156,18 +156,17 @@ certificate. However, this mode of operation is unable to install
 certificates or configure your webserver, because our installer
 plugins cannot reach your webserver from inside the Docker container.
 
-Most users should use the operating system packages (see instructions at
+Most users should use the instructions at certbot.eff.org_. You should only use
-certbot.eff.org_) or, as a fallback, ``certbot-auto``. You should only
+Docker if you are sure you know what you are doing and have a good reason to do
-use Docker if you are sure you know what you are doing and have a
+so.
-good reason to do so.
 
 You should definitely read the :ref:`where-certs` section, in order to
 know how to manage the certs
 manually. `Our ciphersuites page <ciphers.html>`__
 provides some information about recommended ciphersuites. If none of
-these make much sense to you, you should definitely use the
+these make much sense to you, you should definitely use the installation method
-certbot-auto_ method, which enables you to use installer plugins
+recommended for your system at certbot.eff.org_, which enables you to use
-that cover both of those hard topics.
+installer plugins that cover both of those hard topics.
 
 If you're still not convinced and have decided to use this method, from
 the server that the domain you're requesting a certficate for resolves