Add support for CITATION.cff format

NAMESPACE

@@ -95,6 +95,7 @@ export(use_build_ignore)
 export(use_c)
 export(use_cc0_license)
 export(use_ccby_license)
+export(use_cff)
 export(use_circleci)
 export(use_circleci_badge)
 export(use_citation)

R/cff.R

@@ -0,0 +1,22 @@
+#' Create Citation File Format
+#'
+#' `use_cff()` ...
+#'
+#' @seealso The Turing way [tutorial on CFF](https://book.the-turing-way.org/communication/citable/citable-cffinit.html).
+#' @export
+#' @examples
+#' \dontrun{
+#' use_cff()
+#' }
+use_cff <- function() {
+    check_is_package() # CM: Other functions start with this, but not sure if I need it
+    use_template(
+        "CITATION-template.cff",
+        "CITATION.cff",
+        open = TRUE
+    )
+
+    ui_bullets(c(
+        "_" = "Edit `CITATION.cff` (see {.url https://book.the-turing-way.org/communication/citable/citable-cffinit.html} and {.url https://citation-file-format.github.io/cff-initializer-javascript/#/})."
+    ))
+}

_pkgdown.yml

@@ -61,6 +61,7 @@ reference:
     - use_test_helper
     - use_vignette
     - use_addin
+    - use_cff
     - use_citation
     - use_tutorial
     - use_author

inst/templates/CITATION-template.cff

@@ -0,0 +1,17 @@
+# YAML 1.2
+---
+cff-version: "1.2.0"
+title: ""
+authors:
+  -
+    family-names: 
+    given-names: 
+    orcid: "https://orcid.org/0000-0000-0000-0000"
+date-released: 20??-MM-DD
+doi: <insert your DOI here>
+version: ""
+repository-code: ""
+keywords:
+  - keyword1
+message: "If you use this software, please cite it using these metadata."
+license: 

tests/testthat/test-cff.R

@@ -0,0 +1,5 @@
+test_that("use_cff() creates promised file", {
+  create_local_package()
+  use_cff()
+  expect_proj_file("CITATION.cff")
+})