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/stdlib-candidate-older/tests/record.nu

@@ -0,0 +1,20 @@
+use std assert
+use ../std-rfc record
+
+export def "test list_merge" [] {
+    assert equal ([{a:1} {b:2} {c:3} {d:4}] | record list merge) {a:1 b:2 c:3 d:4}
+}
+
+export def "test filter-name predicate" [] {
+    assert equal ({aa:1 ab:2 ba:3 bb:4 ca:5 cb:6} | record filter-name predicate {$in | str contains a}) {aa:1 ab:2 ba:3 ca:5}
+}
+
+export def "test filter-name text" [] {
+    assert equal ({aa:1 ab:2 ba:3 bb:4 ca:5 cb:6} | record filter-name text a) {aa:1 ab:2 ba:3 ca:5}
+    assert equal ({aa:1 ab:2 ba:3 bb:4 ca:5 cb:6} | record filter-name text -r ^a) {aa:1 ab:2}
+    assert equal ({aa:1 ab:2 ba:3 bb:4 ca:5 cb:6} | record filter-name text -r ^A) {}
+}
+
+export def "test filter-value predicate" [] {
+    assert equal ({aa:1 ab:2 ba:3 bb:4 ca:5 cb:6} | record filter-value predicate { $in mod 2 == 0 }) {ab:2 bb:4 cb:6}
+}