znew: add page (#8637)

pages/common/znew.md

@@ -0,0 +1,20 @@
+# znew
+
+> Recompress files from `.Z` to `.gz` format.
+> More information: <https://manned.org/znew>.
+
+- Recompress a file from `.Z` to `.gz` format:
+
+`znew {{path/to/file1.Z}}`
+
+- Recompress multiple files and display the achieved size reduction % per file:
+
+`znew -v {{path/to/file1.Z}} {{path/to/file2.Z}} {{path/to/file3.Z}}`
+
+- Recompress a file using the slowest compression method (for optimal compression):
+
+`znew -9 {{path/to/file1.Z}}`
+
+- Recompress a file, [K]eeping the `.Z` file if it is smaller than the `.gz` file:
+
+`znew -K {{path/to/file1.Z}}`