Adding columns "category" and "comments" to tt show

[v-romana]

"Task Category", "Task", "Description" in tt show table

[eyscode]

Hi @v-romana first of all thanks for your initiative to improve this cli, we really appreciate that, I'm closing this PR tho, due to the following reasons:

• your update ignores full parameter (which is meant to show all fields available for each row). So Task Category, Task and Comments should not be listed when full is False (i.e default behavior).
• https://github.com/eyscode/timetracker/pull/13/files is already covering the changes required to adapt tt to last changes on timetracker website, please check it out.