use_file: Copies local file to app/www

[KasperThystrup]

Made a use_file function that copies a specified local file to the project app/www directory.

This is linked to #465

I added the following new functions:

use_files.R:
use_file(path, name, ...)

utils.R:
cat_start_copy()
cat_copied(where, file = "File")

devtools::check() comes up with two errors

1. Failure: add_files (@test-add_files.R#49)
2. Failure: add_files (@test-add_files.R#49)

Documentation:

I added @param path to the use_files documentation
I used an earlier version of Roxygen, so beware of those potential changes in [man/document_and_reload.Rd]

!This is my very first PR (ever), so please let me know if anything is missing.!

[ColinFay]

Hey,

Thanks 💪

Could you name this use_internal_file() please?

Also, would you fancy making the use_internal_css_file(), use_internal_js_file() and use_internal_html_template()

[KasperThystrup]

Sure thing!

Looking through the external functions, I saw that you use @importFrom fs path_abs, Since you also use fs::file_exists I took a chance and added that to the Roxygen skeleton (and cleaned up the fs:: bits). If you prefer to have it reverted, let me know.

devtools::check() still results in the same two aforementioned failures.

I have only made minimal checks on the js, html, and css file handlers. I can confirm that they provide their respective messages, as well as it copies their target files to the www. js and css also successfully checks for file extensions.

[KasperThystrup]

See #529. (Should I close this request then?)