timetrap: add page (#6925)

pages/common/timetrap.md

@@ -0,0 +1,16 @@
+# timetrap
+
+> Simple command-line time tracker written in Ruby.
+> More information: <https://github.com/samg/timetrap>.
+
+- Create a new timesheet:
+
+`timetrap sheet {{timesheet}}`
+
+- Check in an entry started 5 minutes ago:
+
+`timetrap in --at "{{5 minutes ago}}" {{entry_notes}}`
+
+- Display the current timesheet:
+
+`timetrap display`