javascript - About common module splicing html, css, img, js

Most of the projects I have done recently are similar in length, so I want to extract some individual modules such as module A (may contain img, css, html, js), module B (may contain css, html); make a backend , each independent module can be directly clicked or combined to put the AB... modules into one page, which can be previewed and then downloaded. It is convenient for pages with simple special topics and can be quickly transferred to the back-end children's boots!
I don’t know how to start now. Could you please recommend a tool or this convenient information? Want to know how to splice and how to manage these modules?
The general process and function of what I want to do for the time being is as follows.

A module

<code>  > 生成ab.html > 预览 > 下载（静态资源包） </code>

B module

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Most of the projects I have done recently are similar in length, so I want to extract some individual modules such as module A (may contain img, css, html, js), module B (may contain css, html); make a backend , each independent module can be directly clicked or combined to put the AB... modules into one page, which can be previewed and then downloaded. It is convenient to use for some simple thematic activity pages and quickly throw it to the back-end children's boots!
I don’t know how to start now. Could you please recommend a tool or this convenient information? Want to know how to splice and how to manage these modules?
The general process and function of what I want to do for the time being is as follows.

A module

<code>  > 生成ab.html > 预览 > 下载（静态资源包） </code>

B module