Strip Unicode characters from engine docs (#792)

* remove unicode characters in docs

* it appears that gls and lme output for testing are concordant now

* fix broken bits caused by pillar 1.8.0

* remove em dashes

* change link to quasiquotation resources

Author: topepo

DESCRIPTION

@@ -75,4 +75,4 @@ Encoding: UTF-8
 LazyData: true
 Roxygen: list(markdown = TRUE)
 Config/testthat/edition: 3
-RoxygenNote: 7.2.0.9000
+RoxygenNote: 7.2.1.9000

R/model_object_docs.R

@@ -134,7 +134,7 @@
 #'}
 #'
 #' More information on quosures and quasiquotation can be found at
-#' \url{https://tidyeval.tidyverse.org}.
+#' \url{https://adv-r.hadley.nz/quasiquotation.html}.
 #'
 #' @rdname model_spec
 #' @name model_spec