docs-wide: remove CROPS references

The CROPS[1] project hasn't been updated in two years which makes it
incompatible with our current system requirements.

Remove references to CROPS from the documentation, and in most cases
replace them by mentioning that a container can be used (setup for it
left to the user).

Note that the project is working on reference containers[2] which may
replace this at some point (not confirmed).

[1]: https://github.com/crops/poky-container/
[2]: https://lore.kernel.org/yocto/8286fd3b-1b05-47bf-95e4-0b9f0f5411cb@app.fastmail.com/

(From yocto-docs rev: 9d795bc96ad209c1ab7c007c2aae92b60a5d6ee9)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 95cf1ba327a3bcdabadf0ee96d6bf38d05c4c3dc)
[AG: fix conflicts in start.rst]
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Paul Barker <paul@pbarker.dev>

documentation/brief-yoctoprojectqs/index.rst

@@ -19,11 +19,8 @@ build a reference embedded OS called Poky.
       you want to use Yocto Project on to build an image
       (:term:`Build Host`) is not
       a native Linux system, you can still perform these steps by using
-      CROss PlatformS (CROPS) and setting up a Poky container. See the
-      :ref:`dev-manual/start:setting up to use cross platforms (crops)`
-      section
-      in the Yocto Project Development Tasks Manual for more
-      information.
+      an :wikipedia:`OCI container <Open_Container_Initiative>` (using
+      `Docker <https://www.docker.com/>`__ or `Podman <https://podman.io/>`__).
 
    -  You may use version 2 of Windows Subsystem For Linux (WSL 2) to set
       up a build host using Windows 10 or later, Windows Server 2019 or later.