Add command to view blamed commit's PR

[sekerez]

Is your feature request related to a problem? Please describe.
I'd love it to be easier, given a line of code, to immediately open in my browser the blamed commit's PR. It would be especially useful now that I've started a new job, and I'm learning about the codebase.

Describe the solution you'd like
A command that, given a line of code in a repo, opens the blamed commit's PR in Github, probably with gh pr view

Describe alternatives you've considered
this seems straightforward technically

[linrongbin16]

hi @sekerez, see #91

[sekerez]

Oh - that's too bad that this plugin is not currently maintained 😢 thanks @linrongbin16 !