"Principles" Article

[rrrutledge]

This card tracks the work to create a written article to teach the universal, underlying principles of effective inner source.

The article should be PR'd to https://github.com/InnerSourceCommons/InnerSourceLearningPath/blob/master/introduction/principles.md

[rrrutledge]

The existing article should be updated to include the feedback in #44

[lenucksi]

#87 has the remaining unmerged discussion content from #44 as a PR.

[rrrutledge]

Thanks, Johannes.

[rrrutledge]

See #115 for an update.