Link to topic file rather than alias (tidy eval) (#730)

* Link to topic file rather than alias

This change will prevent Rd warnings during "Install and Restart" on Windows. However, it may make the link more fragile.
r-lib/roxygen2#707
https://stackoverflow.com/questions/48430093/how-do-i-resolve-rd-warning-missing-file-link-when-building-packages-in-rstudi/48478698#48478698

* Manually restore fixes from this PR

* http --> https

* Add a NEWS bullet

NEWS.md

@@ -1,5 +1,9 @@
 # usethis (development version)
 
+* The templates used by `use_pipe()` and `use_tidy_eval()` use a more robust
+  form of cross-reference links, linking to files rather than topics. This
+  should silence some warnings upon installation (#730, #731 @jmgirard).
+
 * `create_from_github()` sets remote tracking branch of `master` to `upstream/master`, when it creates (and clones) a fork (#792).
 
 * `use_pipe()` gains a logical `export` argument, so it can do the setup necessary to use the pipe operator when it is re-exported (`export = TRUE`, which is the default and preserves the previous behaviour) and when it is not (`export = FALSE`) (#783).

inst/templates/tidy-eval.R

@@ -2,17 +2,17 @@
 #'
 #' @description
 #'
-#' * \code{\link[rlang]{sym}()} creates a symbol from a string and
-#'   \code{\link[rlang]{syms}()} creates a list of symbols from a
+#' * \code{\link[rlang:quotation]{sym}()} creates a symbol from a string and
+#'   \code{\link[rlang:quotation]{syms}()} creates a list of symbols from a
 #'   character vector.
 #'
-#' * \code{\link[rlang]{enquo}()} and \code{\link[rlang]{enquos}()}
-#'   delay the execution of one or several function arguments.
-#'   \code{enquo()} returns a single quoted expression, which is like
-#'   a blueprint for the delayed computation. \code{enquos()} returns
-#'   a list of such quoted expressions.
+#' * \code{\link[rlang:quotation]{enquo}()} and
+#'   \code{\link[rlang:quotation]{enquos}()} delay the execution of one or
+#'   several function arguments. \code{enquo()} returns a single quoted
+#'   expression, which is like a blueprint for the delayed computation.
+#'   \code{enquos()} returns a list of such quoted expressions.
 #'
-#' * \code{\link[rlang]{expr}()} quotes a new expression _locally_. It
+#' * \code{\link[rlang:quotation]{expr}()} quotes a new expression _locally_. It
 #'   is mostly useful to build new expressions around arguments
 #'   captured with [enquo()] or [enquos()]:
 #'   \code{expr(mean(!!enquo(arg), na.rm = TRUE))}.
@@ -34,7 +34,7 @@
 #'   name, or would like to enforce this, use \code{as_name()}.
 #'
 #' To learn more about tidy eval and how to use these tools, visit
-#' \url{http://tidyeval.tidyverse.org} and the
+#' \url{https://tidyeval.tidyverse.org} and the
 #' \href{https://adv-r.hadley.nz/metaprogramming.html}{Metaprogramming
 #' section} of \href{https://adv-r.hadley.nz}{Advanced R}.
 #'