roclang 0.2.0

Enhancements:

Enable selection of multiple parameters when using type = "param", in accordance with the update from roxygen2 > 7.1.2 that co-documented parameters should be selected in a whole set when extracting their shared documentation. However, selecting multiple independently documented parameters using type = "param" is still not allowed, since the documentation to diffuse should keep to a single entry per call. To diffuse documentation from multiple independently documented parameters, please call the function on each of them.
Add check on whether the extracted documentation entry is invalid (NA_character_) or multiple. These two cases will now result in error, since in most cases such results are not expected. The documentation entry can be multiple if selecting multiple independently documented parameters using type = "param" (not allowed).
Keep backward compatibility with roxygen2 <= 7.1.2 while accommodating to the changes (tested under roxygen2 = 7.1.1).

Add check on whether a function without specifying package (e.g. filter) appears in multiple packages (e.g. dplyr and stats). This will now result in an error.

Change the test of a function from base package from base::paste function to base::library, since the former will result in <NA> when extracting the documentation for sep on MKL platform, as reported by CRAN.

Update string matches in extract_roc_text.R because of an update in stats::lm() documentation: from \\\\code\{lm\} is used to fit linear models\\. to \\\\code\{lm\} is used to fit linear models, including multivariate ones\\..
Fix some typos in comments.

Fix a bug that fails to cite a parameter if the function is from a loaded/attached package but not explicitly designated, e.g. paste instead of base::paste.

extract_roc_text() now defaults its capitalize argument to NA, leaving the function to keep the first letter of the return as is. Previously the default was TRUE, which would capitalize the first letter anyways if missing.
Add package documentation.

Fix a few typos in README.Rmd and function documentations.
Add single quotes to non-standard words.
Update release status on CRAN and installation methods.
Handle parsing of fun in extract_roc_text() in a safer way using get() with mode = "function"; previously it used rlang::parse_expr() with eval(), which is risky for possible code injection.