Have tool specific commands to provide clarity as well as to provide specific tool options

[hairizuanbinnoorazman]

Preview of CLI:

# List projects found in asana
tasker asana list
tasker github list

# List tasks within projects
tasker asana list --proj=12
tasker github list --proj=54

This is compared to current interface:

# List projects found in asana
tasker list --tool=asana
tasker list --tool=github

# List tasks within projects
tasker list --proj=12 --tool=asana
tasker list --proj=54 --tool=github

Some of the questions to ask ourselves before implementing this feature:

• The question is which approach is clearer/better?
• Does it tie in with the overall goal of the tool to provide a generic CLI access to different task tools out there?
• Would it make more sense to have such tool specific commands to live in their own golang package which wraps that respective tool's API?