dua: add page (#4393)

pages/common/dua.md

@@ -0,0 +1,32 @@
+# dua
+
+> Dua (Disk Usage Analyzer) is a tool to conveniently learn about the usage of disk space of a given directory.
+> More information: <https://github.com/Byron/dua-cli>.
+
+- Analyze specific directory:
+
+`dua {{path/to/directory}}`
+
+- Display apparent size instead of disk usage:
+
+`dua --apparent-size`
+
+- Count hard-linked files each time they are seen:
+
+`dua --count-hard-links`
+
+- Aggregrate the consumed space of one or more directories or files:
+
+`dua aggregate`
+
+- Launch the terminal user interface:
+
+`dua interactive`
+
+- Format printing byte counts:
+
+`dua --format {{metric|binary|bytes|GB|GiB|MB|MiB}}`
+
+- Set the number of threads to be used:
+
+`dua --threads {{count}}`