Implement hidden key in frontmatter

[bmuenzenmeyer]

I've been reconciling https://patternlab.io/docs/documenting-patterns/ with #1208 - I realized that we have support for parsing all these keys, yet core may not do something yet with all of them:

• excludeFromStyleguide
• hidden
• links
• order
• state
• tags
• title

This issue is limited to adding hidden functionality to https://github.com/pattern-lab/patternlab-node/blob/dev/packages/core/src/lib/ui_builder.js#L83-L90

[mfranzke]

This issue is limited to adding hidden functionality to https://github.com/pattern-lab/patternlab-node/blob/dev/packages/core/src/lib/ui_builder.js#L83-L90

... and documenting it on https://patternlab.io/docs/hiding-patterns-in-the-navigation/

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!

[stale]

It's hard to keep track of everything. This issue has been automatically marked as stale because it has not had recent activity, neither from the team nor the community. It will be closed if no further activity occurs. Please consider adding additional info, volunteering to contribute a fix for this issue, or making a further case that this is important to you, the team, and the project as a whole. Thanks!