Update source/handbook/people-group/learning-and-development/learning-sessions/index.html.md, source/handbook/people-group/learning-and-development/index.html.md files

Update source/handbook/people-group/learning-and-development/live-learning/index.html.md, source/handbook/people-group/learning-and-development/index.html.md files

Adding "The Relationship Between Learning and Development and Promotion" section to Learning and Development; cross-linking on relevant Handbook pages

Update source/handbook/people-operations/index.html.md, source/handbook/people-operations/learning-and-development/index.html.md, source/handbook/people-operations/learning-and-development/Manager-development/transition-to-manager.md, source/handbook/people-operations/learning-and-development/manager-development/index.html.md, source/handbook/people-operations/people-operations-metrics/index.html.md, source/handbook/people-operations/people-ops-vision/index.html.md, source/handbook/people-operations/planning/index.html.md, source/handbook/people-operations/promotions-transfers/index.html.md, source/handbook/people-operations/visas/index.html.md files

Update source/handbook/people-operations/learning-and-development/Manager-development/transition-to-manager.md

adding some language around career development roles and responsibilities for team members and managers