update ard_moodtest function to accept multiple variables

[ayogasekaram]

update ard_moodtest() function to accept multiple variables

closes #89

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Pre-review Checklist (if item does not apply, mark is as complete)

• All GitHub Action workflows pass with a ✅
• PR branch has pulled the most recent updates from master branch: usethis::pr_merge_main()
• If a bug was fixed, a unit test was added.
• Code coverage is suitable for any new functions/features (generally, 100% coverage for new code): devtools::test_coverage()
• Request a reviewer

Reviewer Checklist (if item does not apply, mark is as complete)

• If a bug was fixed, a unit test was added.
• Run pkgdown::build_site(). Check the R console for errors, and review the rendered website.
• Code coverage is suitable for any new functions/features: devtools::test_coverage()

When the branch is ready to be merged:

• Update NEWS.md with the changes from this pull request under the heading "# cards (development version)". If there is an issue associated with the pull request, reference it in parentheses at the end update (see NEWS.md for examples).
• All GitHub Action workflows pass with a ✅
• Approve Pull Request
• Merge the PR. Please use "Squash and merge" or "Rebase and merge".

[github-actions]

Code Coverage Summary

Filename                    Stmts    Miss  Cover    Missing
------------------------  -------  ------  -------  ------------------------------------
R/ard_car_anova.R              41       2  95.12%   57, 60
R/ard_chisqtest.R              31       0  100.00%
R/ard_cohens_d.R               73       0  100.00%
R/ard_fishertest.R             33       0  100.00%
R/ard_hedges_g.R               60       0  100.00%
R/ard_kruskaltest.R            27       0  100.00%
R/ard_mcnemartest.R            41       0  100.00%
R/ard_moodtest.R               47       1  97.87%   44
R/ard_proportion_ci.R          40       5  87.50%   63-67
R/ard_proptest.R               71       0  100.00%
R/ard_regression_basic.R       14       1  92.86%   44
R/ard_regression.R             49       0  100.00%
R/ard_smd.R                    40       0  100.00%
R/ard_ttest.R                  78       0  100.00%
R/ard_vif.R                    58       2  96.55%   46, 80
R/ard_wilcoxtest.R             97       2  97.94%   61, 103
R/proportion_ci.R             188      28  85.11%   275, 278, 287-292, 300, 315, 415-438
TOTAL                         988      41  95.85%

Diff against main

Filename            Stmts    Miss  Cover
----------------  -------  ------  -------
R/ard_moodtest.R       +7      +1  -2.13%
TOTAL                  +7      +1  -0.07%

Results for commit: 98e44b1

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[github-actions]

Unit Tests Summary

 1 files  29 suites   4s ⏱️
28 tests 20 ✅  8 💤 0 ❌
71 runs  52 ✅ 19 💤 0 ❌

Results for commit 98e44b1.

[ddsjoberg]

Yasssss 🌈