I’m creating a webapp or I could say a common Markdown editor where user can write markdown and download it’s created markdown in html form but I want also add a feature where non techie user can host their written markdown on github pages as a static html page through my app interface, is here any api that github provide us to do this or any other way to do this, please help?
I am not too sure what you mean here. Do you mean your app is a sort of CMS, which integrates with GitHub’s API, allowing a no-code setup of GitHub Pages?
Or, is it just a case of using GitHub as the host for the data (Markdown files)?
GitHub’s API allows you to do everything through their interface, through an integrated app. So, yes. You just need to request the necessary permissions from the account holder to do this.
GitHub also has extensive documentation for their API, so you should be able to just stick to that.