doc: Add a Dependencies doc page under Development

What does this MR do?

This consolidates the documentation about dependencies and their update.

Review app pages:

• http://main-ee-66626.178.62.207.141.nip.io/ee/development/index.html#processes
• http://main-ee-66626.178.62.207.141.nip.io/ee/development/dependencies.html
• http://main-ee-66626.178.62.207.141.nip.io/ee/development/fe_guide/dependencies.html#updating-dependencies