fill, docstring, istypes, benchmark

[drizk1]

• I was unable to get parse_across to support the predicate functions, so the is_type do not have much functionality right now but included are is_float, is_integer, is_string.

• fill_missing macro + docstring + example

• slice_sample macro + docstring + addended slice in user guide

• added a benchmarking file to the docs. it may totally miss the mark with delivery. I am happy to revise as needed.

[drizk1]

draft.

[drizk1]

Ready for review.

jk not yet.

now its ready. removed is_categorical because I will just throw that in TidierCats to minimize adding new deps.

[kdpsingh]

Thank you for working on this! Will take a look this weekend. My VSCode is acting up right now.

[kdpsingh]

Nice job on fixing the doctests! I'll got through these next week. There's a lot in this PR, so I want to make sure we get each new macro/function right.

I agree with moving is_categorical() into TidierCats.

[drizk1]

Sounds good. Only thing I couldn't figure out was the doc test output for slice_sample because it shows a random set of rows. I tried setting a seed but that did not work either so I suppressed output w ;
I also didn't know if there was another way I should do it beside using randperm

[kdpsingh]

I have ideas on how to fix.

[kdpsingh]

No worries about the failing tests, has to do with dependencies. Will come back to this.