Your question is "Is there any demand for Personal CV/Resume website?". The short answer is: There is demand for
employment.
What problem are you actually trying to solve? If you were looking for a job, would writing a résumé be the biggest hurdle for you?
People write CVs to apply for jobs, and they apply for jobs to work, and they work to have an income which they use to go on about life.
Now, what we have here is selling soap to hungry people who are broke. A CV builder is like soap in a restaurant; it is important to wash your hands at a restaurant, but you don't go to a restaurant to wash your hands.
It can be a hook to do other things, like discover your customers, etc. but your would be users eventually come to you to get a job. How do you get them there? What are the sides of this market?
You have a distribution problem. Ideally, anyone who uses your CV builder gets employed. Which means they get hired. Which means there's an employer on the other side who received that CV. How do you plug in that process?
Maybe go upstream and do some fine targeting, maybe a choice of the point of market entry: start with people who are looking for their first job and who've never had a CV. You shouldn't wait for them to find you; they may not even be aware they need a CV. Maybe you can start with employment agencies where you live. Many countries have agencies where unemployed people register to get notified when a job matching their skills is available. Maybe going to high-schools or colleges and getting your users there, on the spot, helping them making a CV.
Maybe fine-tune where you plug in that value chain: the builder is just to get the data in order to make recommendations to jobs that match their skills that they weren't even aware existed.
Get to know who you're serving and what serving them is about.
This response is about the feasibility of this, not about its viability as a business or if it is worth your while.