Hello,
Could you allow creating an account based on Email + Password?
Thank You.
It is already in there, it needs to be activated in the config, though! If you host your own installation, please change your config.json to contain "email": true somewhere in here (same hierarchical level as "facebook" or "db"):
https://github.com/hackmdio/hackmd/blob/master/config.json.example#L15-L66
In my local config, I removed all other login services, my production config looks like this:

I was talking about the Online Application you have on hackmd.io.
It doesn't allow using Email for Sign In.
I don't have a server to run my own version.
I prefer using the service.
That is a deliberate choice, I do not believe they will change their minds. There was a short statement about it here: https://github.com/hackmdio/hackmd/issues/36#issuecomment-254024336
I see.
Is there any host which have this with this method enabled?
How hard is to set a hosting for that to enable collaboration of a group?
I don't know if there are other public hosts, perhaps someone else knows more about that.
The second question is hard to anwer.
The underlying technologies are NodeJS and an SQL database (most commonly either PostgreSQL or MySQL). How hard setup is, depends on two things: The number of hoops your web hosting company makes you jump through, and your experience with JavaScript and/or web servers. If you have not heard either of these technologies, you may need some guidance or at least you should plan for extended google-sessions.
For your own server, follow the setup instructions.
If you don't plan on managing your own server, I believe this can be deployed to Heroku (basically a provider for web servers) but I haven't tried that, so I'm not exactly sure how well it works. Also the free offer of heroku might or might not be satisfactory for you. If you use this alone, it will most certainly be alright. If you are planning on using it with a large number of people, you might want to spend a few bucks for hosting.
As already mentioned this won't be fixed on HackMD.io for now. https://github.com/hackmdio/hackmd/issues/36#issuecomment-254024336
Most helpful comment
I don't know if there are other public hosts, perhaps someone else knows more about that.
The second question is hard to anwer.
The underlying technologies are NodeJS and an SQL database (most commonly either PostgreSQL or MySQL). How hard setup is, depends on two things: The number of hoops your web hosting company makes you jump through, and your experience with JavaScript and/or web servers. If you have not heard either of these technologies, you may need some guidance or at least you should plan for extended google-sessions.
For your own server, follow the setup instructions.
If you don't plan on managing your own server, I believe this can be deployed to Heroku (basically a provider for web servers) but I haven't tried that, so I'm not exactly sure how well it works. Also the free offer of heroku might or might not be satisfactory for you. If you use this alone, it will most certainly be alright. If you are planning on using it with a large number of people, you might want to spend a few bucks for hosting.