List per user notifications

[PeterDaveHello]

Not sure if you'd like to have this feature, just list all the notifications of my GitHub account, looks very useful to me :)

[henvic]

It would be cool and I would merge a pull request for that.

I shouldn't be able to work on this myself anytime soon.

[protoEvangelion]

Looks like this can be easily achieved with the newly added octokit api: https://octokit.github.io/rest.js/#octokit-routes-activity-list-notifications

For an example use the latest cmd:

gh/src/cmds/notification.ts

Line 80 in c1f8cf2

Notifications.prototype.latest = async function(opt_watch) {

We could add a new flag like --list