Add interpretation for fei effect size

[rempsyc]

Closes #608

---

library(effectsize)
packageVersion("effectsize")
#> [1] '0.8.6.1'

htest <- chisq.test(table(mtcars$cyl), p = c(0.1, 0.3, 0.6))

x <- effectsize(htest)

effectsize::interpret(x, rules = "funder2019")$Interpretation
#> [1] "medium"
#> (Rules: funder2019)

effectsize::interpret(x, rules = "funder2019")
#> Fei  |       95% CI | Interpretation
#> ------------------------------------
#> 0.27 | [0.17, 1.00] |         medium
#> 
#> - Adjusted for uniform expected probabilities.
#> - One-sided CIs: upper bound fixed at [1.00].
#> - Interpretation rule: funder2019

^{Created on 2023-09-24 with reprex v2.0.2}

[codecov[bot]]

Codecov Report

Merging #609 (c5366a5) into main (14e388d) will not change coverage. The diff coverage is 100.00%.

:exclamation: Current head c5366a5 differs from pull request most recent head 6631551. Consider uploading reports for the commit 6631551 to get more accurate results

@@           Coverage Diff           @@
##             main     #609   +/-   ##
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  Coverage   90.55%   90.55%           
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  Files          56       56           
  Lines        3419     3419           
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  Hits         3096     3096           
  Misses        323      323           

Files	Coverage Δ
R/interpret.R	91.01% <100.00%> (ø)
R/interpret_r.R	100.00% <ø> (ø)