[Feature] Pull Request Auto Labeler

[trsvchn]

This PR adds automatic issue and pr labelers

Issue labeler adds labels based on the body content of the issue.

PR labeler adds labels s based on the paths that are modified in the PR.

Description:

Here is demo from my fork:

trsvchn#13
trsvchn#14

All labels are defined in config files in .github/*-labeler.yml

Some of them are disabled:

https://github.com/trsvchn/ignite/blob/b55ce8331316cba55b2d5cb12fe9c26d6182b067/.github/pr-labeler.yml#L9-L20

Since we need to create them in repo first, action doesn't create them for us just uses already available.

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

Looks very cool @trsvchn ! Thanks for the FR !

[trsvchn]

@vfdev-5 Please see the following experiments:

trsvchn#13 (comment)

[trsvchn]

Issue labeler removes manually added labels

[vfdev-5]

Yes, looks like that...

[trsvchn]

As possible solution, we can use it only on issue opening, to label it once

[trsvchn]

Or create a subset of labels just for labeler: a kind of:

• "triage: docs"
• "triage: docker"
• etc

[trsvchn]

@vfdev-5

I've removed triggering on issue editing for Issue Labeler, since we are actively using labels on issues, So we will have only one labeling on opening issue, and then we can add some labels with no worries.

Triggering for PR Labeler left unchanged, since I've noticed we are not using labels for PR at all, so it is not going to affect any labeling system.

[sdesrozis]

@trsvchn Beyond technical issues that you are facing, I really enjoy this FR :)

[trsvchn]

@sdesrozis Thanks!) Yes, I'm looking for solution where we can "coexist" with auto-labeling system, since labelers don't have a clue who added this label etc, and there is no way to inform them: "I know no docs are modified, but this PR/issue is logically connected to docs"

[vfdev-5]

Looks good ! Thanks @trsvchn