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

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

---------

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

pages/common/combine.md

@@ -0,0 +1,22 @@
+# combine
+
+> Perform set operations on lines of two files.
+> The order of the output lines is determined by the order of the lines in the first file.
+> See also: `diff`.
+> More information: <https://joeyh.name/code/moreutils/>.
+
+- Output lines that are in both specified files:
+
+`combine {{path/to/file1}} and {{path/to/file2}}`
+
+- Output lines that are in the first but not in the second file:
+
+`combine {{path/to/file1}} not {{path/to/file2}}`
+
+- Output lines that in are in either of the specified files:
+
+`combine {{path/to/file1}} or {{path/to/file2}}`
+
+- Output lines that are in exactly one of the specified files:
+
+`combine {{path/to/file1}} xor {{path/to/file2}}`