xml: draft all but 3 most complex subcommands

pages/common/xml-depyx.md

@@ -1,8 +1,16 @@
 # xml-depyx
 
-> XMLStarlet toolkit: Convert a PYX document to XML format. (ESIS - ISO 8879).
+> Convert a PYX (ESIS - ISO 8879) document to XML format.
 > More information: <http://xmlstar.sourceforge.net/docs.php>.
 
+- Convert a PYX (ESIS - ISO 8879) document to XML format:
+
+`xml depyx {{path/to/input.pyx|URI}} >{{path/to/output.xml}}`
+
+- Convert a PYX document from standard input to XML format:
+
+`cat {{path/to/input.pyx}} | xml depyx >{{path/to/output.xml}}`
+
 - Display help for `depyx` subcommand:
 
 `xml depyx --help`