Deprecate the nu_scripts version of stdlib-candidate (#1042)

Deprecates the existing `stdlib-candidate` directories in `nu_scripts`
since `std-rfc` has now transitioned to the main repo. Updates readme
and renamed directories.

stdlib-candidate-archive/std-rfc/clip/mod.nu

@@ -0,0 +1,71 @@
+# Commands for interacting with the system clipboard
+#
+# > These commands require your terminal to support OSC 52
+# > Terminal multiplexers such as screen, tmux, zellij etc may interfere with this command
+
+# Copy input to system clipboard
+#
+# # Example
+# ```nushell
+# >_ "Hello" | clip copy
+# ```
+export def copy [
+  --ansi (-a)                 # Copy ansi formatting
+]: any -> nothing {
+  let input = $in | collect
+  let text = match ($input | describe -d | get type) {
+    $type if $type in [ table, record, list ] => {
+      $input | table -e
+    }
+    _ => {$input}
+  }
+
+  let do_strip_ansi = match $ansi {
+    true  => {{||}}
+    false => {{|| ansi strip }}
+  }
+
+  let output = (
+    $text
+    | do $do_strip_ansi
+    | encode base64
+  )
+
+	print -n $'(ansi osc)52;c;($output)(ansi st)'
+}
+
+# Paste contenst of system clipboard
+#
+# # Example
+# ```nushell
+# >_ clip paste
+# "Hello"
+# ```
+export def paste []: [nothing -> string] {
+	try {
+		term query $'(ansi osc)52;c;?(ansi st)' -p $'(ansi osc)52;c;' -t (ansi st)
+	} catch {
+		error make -u {
+			msg: "Terminal did not responds to OSC 52 paste request."
+			help: $"Check if your terminal supports OSC 52."
+		}
+	}
+	| decode
+	| decode base64
+	| decode
+}
+
+# Add a prefix to each line of the content to be copied
+#
+# # Example: Format output for Nushell doc
+# ls | clip prefix '# => ' | clip copy
+export def prefix [prefix: string]: any -> string {
+  let input = $in | collect
+  match ($input | describe -d | get type) {
+    $type if $type in [ table, record, list ] => {
+      $input | table -e
+    }
+    _ => {$input}
+  }
+  | str replace -r --all '(?m)(.*)' $'($prefix)$1'
+}