tools: ynl: cli: wrap the doc text if it's long

tools: ynl: cli: wrap the doc text if it's long

We already use textwrap when printing "doc" section about an attribute,
but only to indent the text. Switch to using fill() to split and indent
all the lines. While at it indent the text by 2 more spaces, so that it
doesn't align with the name of the attribute.

Before (I'm drawing a "box" at ~60 cols here, in an attempt for clarity):

 |  - irq-suspend-timeout: uint                              |
 |    The timeout, in nanoseconds, of how long to suspend irq|
 |processing, if event polling finds events                  |

After:

 |  - irq-suspend-timeout: uint                              |
 |      The timeout, in nanoseconds, of how long to suspend  |
 |      irq processing, if event polling finds events        |

Tested-by: Gal Pressman <gal@nvidia.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20260110233142.3921386-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>