Issue with Self-Contained docToolchain Setup – Plugin Resolution Error

Hi everyone,

I followed this tutorial exactly as described:
https://doctoolchain.org/docToolchain/v2.0.x/020_tutorial/120_self-contained-dtc.html

However, when running `dtcw.bat GenerateSite`, I encounter the following error:

```
FAILURE: Build failed with an exception.

* Where:
Build file 'C:\Users\\.doctoolchain\docToolchain-3.4.1\build.gradle' line: 26

* What went wrong:
Plugin [id: 'org.aim42.htmlSanityCheck', version: '2.0.0-rc0'] was not found in any of the following sources:

- Gradle Core Plugins (plugin is not in 'org.gradle' namespace)
- Included Builds (No included builds contain this plugin)
- Plugin Repositories (could not resolve plugin artifact 'org.aim42.htmlSanityCheck:org.aim42.htmlSanityCheck.gradle.plugin:2.0.0-rc0')
Searched in the following repositories:
Gradle Central Plugin Repository
```
The `build.gradle file` references the following plugins that seem to be causing the issue:

plugins {
alias(libs.plugins.htmlSanityCheck)
alias(libs.plugins.versions)
alias(libs.plugins.openapi.generator)
alias(libs.plugins.undercouch.download)
alias(libs.plugins.jbake.site)
}

How can I ensure these plugins are available in a self-contained docToolchain setup, so that `dtcw `executes successfully without internet access?

Thanks in advance!

Best regards
Dave

Start with the self-contained setup tutorial and build.gradle line 26, then reproduce dtcw.bat GenerateSite without internet access. Trace how the listed plugins are resolved; done means the self-contained setup can execute successfully offline with all required plugins available.

Written by the indexing model from the issue text.