DOC: update style.ipynb for 2.0

[attack68]

This PR tries to frame Styler more as a general display output tool, by including the more generalist "formatting" functions at the start,

[mroeschke]

nbclient.exceptions.CellExecutionError: An error occurred while executing the following cell:
------------------
df = pd.DataFrame({
    "strings": ["Adam", "Mike"],
    "ints": [1, 3],
    "floats": [1.123, 1000.23]
})
df.style \
  .format(precision=3, thousands=".", decimal=",") \
  .format_index(str.upper, axis=1) \
  .relabel_index(["row 1", "row 2"], axis=0)
------------------

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In[1], line 1
----> 1 df = pd.DataFrame({
      2     "strings": ["Adam", "Mike"],
      3     "ints": [1, 3],
      4     "floats": [1.123, 1000.23]
      5 })
      6 df.style \
      7   .format(precision=3, thousands=".", decimal=",") \
      8   .format_index(str.upper, axis=1) \
      9   .relabel_index(["row 1", "row 2"], axis=0)

NameError: name 'pd' is not defined
NameError: name 'pd' is not defined

Notebooks DONE

[mroeschke]

Thanks @attack68