Adding "setting up prettier" in CONTRIBUTING.md

[sainthkh]

Summary

In #16514, prettier was set up for Kibana. And styleguide recommends to use it, but prettier wasn't mentioned in CONTRIBUTING.md.

So, I've added some explanation and setup guide.

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

• This was checked for cross-browser compatibility, including a check against IE11
• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Pinging @elastic/kibana-operations

[jbudz]

Thanks @sainthkh! small comment above

[sainthkh]

Removed contents about prettier.

Still, I have a question about prettier:

It is not wrong to install 'prettier' plugin on VS Code and use them whenever file is saved. Right? I guess .prettierrc wouldn't exist if it should be avoided.

I became curious about this because currently eslint doesn't check no trailing comma as an error but .prettierrc automatically adds it.

[jbudz]

I wouldn't recommend using the prettierrc plugin in vscode - it will read the prettierrc but we have overrides in places that eslint will manage differently.

roughly the workflow is

eslint config + prettier - (rules where eslint overrides prettier)

[jbudz]

@elasticmachine merge upstream

[jbudz]

nice, thanks @sainthkh.

retest

[sainthkh]

OK. I'll turn prettier plugin off. Thanks.

[spalger]

LGTM, maybe it's best to explicitly mention that the prettier plugin shouldn't be used in Kibana. Primarily because not all files are supposed to be prettierified and that configuration is in the eslint config not in a .prettierignore file or something (so the prettier plugin applies to too many files).

[sainthkh]

@spalger I agree. So, I've added a warning to the VS code setting section.

[spalger]

LGTM

[tylersmalley]

retest

[spalger]

@elasticmachine merge upstream

[jbudz]

@elasticmachine merge upstream - sorry for all the pings, jenkins went down this time. one more time, I'll override if we're still red

[tylersmalley]

@elasticmachine merge upstream

[tylersmalley]

Merging since this is docs.

[tylersmalley]

7.x/7.5: 88a4db0