Update writer table docs

[gerritholl]

Update the writer table documentation. Change the CF writer classification from pre-alpha to beta. Clarify the status of the ninjotiff/ninjogeotiff writer pair in relation to NinJo versions.

• Fully documented

[codecov]

Codecov Report

Merging #2225 (76703ce) into main (7a30eb8) will increase coverage by 0.00%.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             main    #2225    +/-   ##
========================================
  Coverage   94.13%   94.14%            
========================================
  Files         293      294     +1     
  Lines       45079    45183   +104     
========================================
+ Hits        42437    42539   +102     
- Misses       2642     2644     +2     

Flag	Coverage Δ
behaviourtests	4.67% <ø> (-0.01%)	⬇️
unittests	94.79% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
satpy/readers/seadas_l2.py	96.84% <0.00%> (-1.28%)	⬇️
satpy/composites/ahi.py	100.00% <0.00%> (ø)
satpy/tests/reader_tests/test_abi_l2_nc.py	100.00% <0.00%> (ø)
satpy/composites/spectral.py	100.00% <0.00%> (ø)
satpy/tests/test_scene.py	99.49% <0.00%> (+<0.01%)	⬆️
satpy/scene.py	93.37% <0.00%> (+0.01%)	⬆️
satpy/readers/abi_base.py	94.52% <0.00%> (+0.07%)	⬆️
satpy/tests/reader_tests/test_seadas_l2.py	99.07% <0.00%> (+0.40%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[coveralls]

Coverage remained the same at 94.747% when pulling 76703ce on gerritholl:nc-status into 6d24db1 on pytroll:main.

[mraspaud]

LGTM