I write about creating developer categories for dev tool startup founders. I founded or was the first VP of Marketing for 12 startups, including 3 unicorns.
Sell the category.
I have been the first Marketing VP at 3 dev facing unicorns, and I share some of the things I have learned the hard way.
If you are creating a category, sell the category. If you are not creating a category, stop reading--I have nothing to teach you.
Your content plan is all about the category. Where it came from, why it is needed now, where it is going, and what the big undeniable trends that are pushing the category are.
Don't sell your product.
Instead, let your users sell your product. If your user didn't say it, it isn't believable anyway. Your top priority after getting users is documenting user value.