Hugo isn't making different pages for categories and tags

Hi, I’m making a theme for my blog and facing a strange problem.

Instead of showing a list of posts on one specific tag/category on its specific URL like http://localhost:1313/categories/mycategory/ I’m seeing the whole of the data including all of the other categories/tags.

In my case, Hugo is either not generating pages for each category/tag or something else. I suggest you check theme repo here.
Simply, when I click on a category, suppose JavaScript, the link opens at the correct place(URL) i.e. http://localhost:1313/categories/javascript/ but shows all of the posts exactly as do on the home page instead of showing only that specific posts. Same behavior for tags. Why is that? Do I have to make list pages for each category and tag which I know not the case.

Your theme has a list.html and a single.html. As you don’t have a layout file that is more specific, the tags and categories pages will default to using this same list.html.

In this list.html layout:

{{-  range where .Site.RegularPages "Section" "posts" -}}

you range through your posts pages. It will give you the same result whether you are on the homepage, section page, or indeed tag page. Have a read about Taxonomy templates here.

Hi, thanks for the response.

Till now I’ve taken the reference of more than five themes and they work fine. They also don’t have any taxonomy specific template but things are fine.
I created taxonomy.html below layouts/ and added in it following lines of code

{{ range where .Site.RegularPages "Type" "Taxonomies" }}
    <a href="{{.Permalink}}">Read more</a>
{{ end }}

But when I go to http://localhost:1313/categories/javascript/ nothing appears there. Everything was running smooth as I created this theme in just 5 hours but at this problem I’m struck for a week.
Can you please write a little bit code here or eleborate it?
Thanks a lot!