DOC: Remove makePanel from docs (#25609)

[ArtificialQualia]

• closes Remove makePanel Calls in Docs #25609
• tests added / passed
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

As described in #25609, I removed the tm.makePanel() calls from the docs, along with some of the surrounding sections (a few "Deprecate Panel" sections). I did not replace these calls with an equivalent manual creation of a Panel.

If desired, I could create a panel manually in the docs with something like this:

cols = ['Item' + c for c in string.ascii_uppercase[:K - 1]]	
data = {c: tm.makeTimeDataFrame() for c in cols}	
p = Panel.fromDict(data)

but this PR is currently as requested in the issue with the sections removed.

[codecov]

Codecov Report

Merging #25612 into master will decrease coverage by 49.55%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master   #25612       +/-   ##
===========================================
- Coverage   91.26%   41.71%   -49.56%     
===========================================
  Files         173      173               
  Lines       52968    52968               
===========================================
- Hits        48339    22093    -26246     
- Misses       4629    30875    +26246

Flag	Coverage Δ
#multiple	?
#single	41.71% <ø> (-0.01%)	⬇️

Impacted Files	Coverage Δ
pandas/io/formats/latex.py	0% <0%> (-100%)	⬇️
pandas/core/categorical.py	0% <0%> (-100%)	⬇️
pandas/io/sas/sas_constants.py	0% <0%> (-100%)	⬇️
pandas/tseries/plotting.py	0% <0%> (-100%)	⬇️
pandas/tseries/converter.py	0% <0%> (-100%)	⬇️
pandas/io/formats/html.py	0% <0%> (-99.36%)	⬇️
pandas/core/groupby/categorical.py	0% <0%> (-95.46%)	⬇️
pandas/io/sas/sas7bdat.py	0% <0%> (-91.17%)	⬇️
pandas/io/sas/sas_xport.py	0% <0%> (-90.15%)	⬇️
pandas/core/tools/numeric.py	10.44% <0%> (-89.56%)	⬇️
... and 130 more

---

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[codecov]

Codecov Report

Merging #25612 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #25612   +/-   ##
=======================================
  Coverage   91.26%   91.26%           
=======================================
  Files         173      173           
  Lines       52968    52968           
=======================================
  Hits        48339    48339           
  Misses       4629     4629

Flag	Coverage Δ
#multiple	89.83% <ø> (ø)	⬆️
#single	41.71% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0d893d0...14dd01a. Read the comment docs.

[ArtificialQualia]

I've converted all the old whatsnew entries to code-blocks using what was in the stable docs. I did not do that for the 'Deprecate Panel' section in dsintro, if you would like me to do it there as well just let me know.

[WillAyd]

General approach lgtm though you have some lint failures in CI - could you take a look?

[ArtificialQualia]

I've fixed the linting errors. I did have to add a # noqa E999 in v0.13.1.rst as flake8-rst was unable to parse that code-block.

[WillAyd]

lgtm @jreback

[jreback]

thanks @ArtificialQualia