is html a programming language

1HTML is a markup language. We don't say HTML as a programming language.

1html has a <script> tag, so it's a superset of javascript

1"NO"

1HTML on its own is not a programming language. 
2Why? Because it's not Turing complete. 
3What? Read about Turing completeness and the universal Turing machine to understand this.
4
5But... CSS + HTML + user interactivity = a programming language.
6CSS has functions (for example, the url function), variables, import statements, conditions (media queries and selectors) and even loops (animations).
7But CSS is nothing without HTML, you can't "execute" CSS code without HTML.
8That's why if you think about them separetly, they are not programming languages.
9But if you add interactivity (like input tags, buttons, etc), CSS and HTML, they make a Turing Complete programming language.

1print('''
2
3It all depends on what you think. It is a markup language, but can
4also interact with the user and can therefore technically be considered
5a programming language
6
7''')