chronic, combine, ifdata, ifne, isutf8: add pages (#12114)

* chronic, combine, ifdata, ifne, isutf8: add pages

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Co-authored-by: Vitor Henrique <87824454+vitorhcl@users.noreply.github.com>

pages/common/ifne.md

@@ -0,0 +1,12 @@
+# ifne
+
+> Run a command depending on the emptyness of `stdin`.
+> More information: <https://joeyh.name/code/moreutils/>.
+
+- Run the specified command if and only if `stdin` is not empty:
+
+`ifne {{command options ...}}`
+
+- Run the specified command if and only if `stdin` is empty, otherwise pass `stdin` to `stdout`:
+
+`ifne -n {{command options ...}}`