Add PR checks via GitHub actions

[ckadner]

GitHub actions along with concise Bash scripts could/should be employed to make sure the submitted "qna.yml" and "knowledge.md" files are formatted correctly (style and content structure)

[ckadner]

I'd be happy to take a first stab at it :-)

[oindrillac]

Checks on PR would be useful. Would reduce the reliance on reviewers and the error handling on the processing backend to weed out incorrectly formatted yamls.

[jeremyeder]

@ckadner please do it -- it should be possible for users to re-run those checks by using slash-commands against our github bot. @Tomcli did that, hopefully he can help integrate (e.g. /test)

[Tomcli]

Github actions will rerun when a new commit is pushed in the PR. To enable retest command on prow, we need to deploy the full prow cluster. The github action version of prow only support the following commands:
Available github action prow commands: https://github.com/jpmcb/prow-github-actions/blob/main/docs/commands.md
Full prow feature for retest github actions: kubernetes/test-infra#31132

[wking]

sounds like there is some CLI-side work in this space: instructlab/instructlab#133 and instructlab/instructlab#205.

[iranzo]

#60 does some checking automatically, we need to just enable the CI run of precommit on the new PR's via #93

[ckadner]

I made the DCO check mandatory and added a simple YAML linter for qna.yaml files yesterday 2a15c43

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An example of linter completing successfully in a few seconds:

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An example of linter catching formatting errors:

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Which also shows the offensive lines in the Files changed view for reviewers:

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My intention is to re-use what @lehors has code in instructlab/instructlab#133 and instructlab/instructlab#205 in a second iteration.