ref-manual/system-requirements.rst: recommend buildtools for not supported distros

From: Michael Opdenacker <michael.opdenacker@bootlin.com>

Also minor correction to supported distribution notes

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Suggested-by: Alexander Kanavin <alex.kanavin@gmail.com>
---
 documentation/ref-manual/system-requirements.rst | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Which is done by running scripts/install-buildtools and doing that has
its own section in the same system-requirements.rst
:-) A simple reference to it should be enough.

Alex

On Thu, 5 Jan 2023 at 16:20, <michael.opdenacker@bootlin.com> wrote:
>
> From: Michael Opdenacker <michael.opdenacker@bootlin.com>
>
> Also minor correction to supported distribution notes
>
> Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
> Suggested-by: Alexander Kanavin <alex.kanavin@gmail.com>
> ---
>  documentation/ref-manual/system-requirements.rst | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/documentation/ref-manual/system-requirements.rst b/documentation/ref-manual/system-requirements.rst
> index 1f9b3b1b58..2bb813b385 100644
> --- a/documentation/ref-manual/system-requirements.rst
> +++ b/documentation/ref-manual/system-requirements.rst
> @@ -34,8 +34,7 @@ and conceptual information in the :doc:`/overview-manual/index`.
>  Supported Linux Distributions
>  =============================
>
> -Currently, the Yocto Project is supported on the following
> -distributions:
> +Currently, the Yocto Project is supported on the following distributions:
>
>  -  Ubuntu 18.04 (LTS)
>
> @@ -71,7 +70,11 @@ distributions:
>        has no plans to support rolling-releases or development
>        distributions due to their constantly changing nature. We welcome
>        patches and bug reports, but keep in mind that our priority is on
> -      the supported platforms listed below.
> +      the supported platforms listed above.
> +
> +   -  If your Linux distribution is not in the above list, we recommend to
> +      get the :term:`buildtools` or :term:`buildtools-extended` tarballs
> +      containing the host tools required by your Yocto Project release.
>
>     -  You may use Windows Subsystem For Linux v2 to set up a build host
>        using Windows 10 or later, or Windows Server 2019 or later, but validation
> --
> 2.37.2
>

On 05.01.23 at 16:38, Alexander Kanavin wrote:
> Which is done by running scripts/install-buildtools and doing that has
> its own section in the same system-requirements.rst
> :-) A simple reference to it should be enough.
>
> Alex


Right, I wanted to minimize the text (as the section is referred to in 
the description of "builttools"), but it's true a direct reference will 
help.

Thanks
Michael.