druid docs: Restore SQL function examples

This PR restores the SQL function examples from @edgar2020. They were previously reverted so that page didn't have examples for some functions and not others. Now that the 31 branch is cut, we're restoring the examples into the master branch and will continue to add the rest.

Oct 08 '24 20:10 vtlim

note: converting to draft to prevent any accidental merge

Oct 09 '24 17:10 techdocsmith

~~i think a spelling error got merged here, see https://github.com/apache/druid/actions/runs/12958051732/job/36147606890#step:5:81~~

> spellcheck
> mdspell --en-us --ignore-numbers --report '../docs/**/*.md' || (./script/notify-spellcheck-issues && false)

    ../docs/querying/sql-functions.md
      175 | ing example returns the state abbrevation, state name, and average flig 

>> 1 spelling error found in 261 files

Oh i se the linked PR, will approve it to fix stuff

Jan 25 '25 00:01 clintropolis