Minor fixes

• We now focus the last executed task. → closes #27

More info

• Starting Compiler.nvim v3.3.7, the minimum required overseer version is 1.5.0.
• Tested with commit stevearc/overseer.nvim@29dd31d.

You can just copy paste the config from here.

Special thanks

@aaronmcadam for reporting the issue and @stevearc for fixing it.