calcurse: add page (#2995)

pages/linux/calcurse.md

@@ -0,0 +1,24 @@
+# calcurse
+
+> A text-based calendar and scheduling application for the command line.
+> Homepage: <https://calcurse.org>.
+
+- Start calcurse on interactive mode:
+
+`calcurse`
+
+- Print the appointments and events for the current day and exit:
+
+`calcurse --appointment`
+
+- Remove all local calcurse items and import remote objects:
+
+`calcurse-caldav --init=keep-remote`
+
+- Remove all remote objects and push local calcurse items:
+
+`calcurse-caldav --init=keep-local`
+
+- Copy local objects to the CalDAV server and vice versa:
+
+`calcurse-caldav --init=two-way`