Resolve warnings in documentation

[andreas-el]

reading sources... [100%] index
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:1133: ERROR: Error in "code" directive:
maximum 1 argument(s) allowed, 5 supplied.

.. code:: python
   from resdata.summary import Summary

   sum = Summary("/path/CASE.DATA")
   days = sum.days
   wwct = sum.numpy_value("WWCT:OP_1")
   wopr = sum.numpy_value("WOPR:OP_1")

   for (d, w, o) in zip(days, wwct, wopr):
       print "%5.0f   %5.3f  %8.1f" % (d,w,o) [docutils]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/index.rst:2: WARNING: Title underline too short.

looking for now-outdated files... none found
Welcome to Resdata documentation!
=============================== [docutils]
pickling environment... done
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/api/modules.rst: WARNING: document isn't included in any toctree [toc.not_included]
checking consistency... done
preparing documents... done
copying assets... 
copying static files... 
Writing evaluated template result to /home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/html/_static/language_data.js
Writing evaluated template result to /home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/html/_static/documentation_options.js
Writing evaluated template result to /home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/html/_static/basic.css
Writing evaluated template result to /home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/html/_static/classic.css
Writing evaluated template result to /home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/html/_static/sidebar.js
copying static files: done
copying extra files... 
copying extra files: done
copying assets: done
writing output... [ 33%] api/modules
writing output... [ 67%] code/index
writing output... [100%] index
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:91: WARNING: undefined label: 'python_documentation' [ref.ref]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:147: WARNING: undefined label: 'python_documentation' [ref.ref]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:279: WARNING: undefined label: 'python_documentation' [ref.ref]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:422: WARNING: undefined label: 'python_documentation' [ref.ref]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:639: WARNING: undefined label: 'python_documentation' [ref.ref]
/home/runner/work/fmu-docs/fmu-docs/resdata/build/doc_build/code/index.rst:705: WARNING: undefined label: 'python_documentation' [ref.ref]
generating indices... genindex done

Ref.
https://github.com/equinor/fmu-docs/actions/runs/14193908330/job/39764554305?pr=150