Bug in error message for invalid IS method + several documentation typos

[ishaan-arora-1]

Hi! I was reading through the codebase and noticed a small bug and a few typos scattered across the source and docs.

Bug: implemented_is_methods called without parentheses

In R/importance_sampling.R (line 117), implemented_is_methods is referenced without () inside the paste0() call:

paste0(implemented_is_methods, collapse = "', '")

Since implemented_is_methods is a function (defined on line 121), this pastes the function object's string representation instead of the actual method names ("psis", "tis", "sis"). The check on line 113 correctly uses implemented_is_methods() with parentheses, but the error message construction doesn't.

Typos in documentation (roxygen + .Rd files)

While reading through the code I also spotted a handful of typos:

File	Typo	Fix
R/diagnostics.R (line 14)	"dependend"	"dependent"
R/diagnostics.R (line 433)	"dependend k-ht"	"dependent k-hat"
R/loo-glossary.R (line 10)	"The pages provides definitions to"	"The page provides definitions of"
R/split_moment_matching.R (line 24)	"log-likeliood"	"log-likelihood"
R/loo_subsample.R (line 420)	"subampled"	"subsampled"
R/loo_compare.psis_loo_ss_list.R (line 34)	"comaprison"	"comparison"
R/loo_model_weights.R (line 10)	"matrices or , one for each"	"matrices, one for each"
R/loo-package.R (line 85)	"widely application"	"widely applicable"

The corresponding .Rd man pages have the same typos (generated from roxygen).

Happy to submit a PR for these if that would be helpful!