ci: fix benchmark workflow, move docs to gh-pages

[alvicsam]

PR fixes script for benchmarks and adds workflow for automatic publishing docs.

@TarikGul @Imod7 docs workflow now works only if files in the docs folder has changed. Is it ok?

cc https://github.com/paritytech/ci_cd/issues/1086

[Imod7]

Thank you @alvicsam for this follow up PR.

Regarding the docs workflow, we need it to run when :

• the src/openapi-v1.yaml is updated/changed
• and as soon as a PR that changes this file is merged in master branch

There is also the case where we update the docs folder by changing the package.json file so in this case we do not need the docs to be published again. It does not do any harm if we do publish but it is not necessary.

[alvicsam]

@Imod7

Both conditions are now in the workflow

[Imod7]

Thank you for the last changes! It looks great!
I have one last question : Since in the gh-pages branch under dev/bench we have a data.js, I would expect that these graphs would be populated already but they are not. Is that expected ?

EDIT : Question already answered int he chat: I will check again when the benchmarks workflow runs. Thank you!