Update for bi-annual cadence

Why is this change being made?

We have received feedback that our quarterly process is a significant effort across the company for both leadership and the People Group. Iterating towards a bi-annual cadence will increase scalability by streamlining this process, while still facilitating multiple opportunities per year for promotions. This iteration will also enable increased efficiency in our process by aligning promotions more closely to our Talent Assessment and Mid-Year cycles, when performance and growth conversations are top of mind.

Update for bi-annual promo cadence. Same info @gl-peoplepartners reviewed here

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