Publish an announcement of the alpha phase when we branch to the next major

[marybaum]

While we make it a practice to branch Trunk for the next major at RC1 or 2 of the current cycle, we don't explicitly announce that's the true beginning of the alpha cycle.

Then, when we announce the beginning of the release cycle in devchat, a lot of people are blindsided when we say it's four weeks to beta.

I propose we publish a post in Make and News at the time of branch so people start working eight, ten, twelve or however many weeks ahead on their pet projects, so they come to the Final Four (weeks that is, until beta) with beta-ready code.

[kittenkamala]

Maybe making a re-useable template for this would help make this process faster and more tangible?

[francescamarano]

@marybaum as discussed, please let's try to get a brief announcement out today about it that highlights both what this means but also that people shouldn't abandon 5.4 :) Thanks!