taskwarrior: Add tim alias for timewarrior

`tim` is intended as a quick support alias for timewarrior.

If invoked without any arguments, `tim` will print out a simple summary
of all tasks accomplished (for the day by default). It will also print
their ids for simple subsequent modification tasks.

If, however, invoked with additional arguments, `tim` will pass anything
along to timewarrior so anything happens as usual if invoked like this.

Thus, `tim` functions as a quick look into the day's timesheet or a
shorter alternative to the `timew` command.

taskwarrior/.config/sh/alias.d/timewarrior.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env sh
+
+if ! exist timew; then
+    return 1
+fi
+
+# invoking tim without arguments prints out timesheet summary
+# with ids attached.
+# otherwise tim passes through any arguments to timew
+tim() {
+    if [ "$#" -eq 0 ]; then
+        timew summary :ids
+    else
+        timew "$@"
+    fi
+}