Publish latest Dokka docs to GitHub Pages

[hbmartin]

Summary

• publish the latest public Dokka HTML directly at the GitHub Pages root
• scope Pages permissions and serialize deployments on successful main pushes
• make public-only visibility explicit and correct source links to lib/src/main/java
• retain the module overview while removing the undeployed Markdown footer link
• remove the obsolete version-index and sitemap scripts
• document the live site and local generation command in the project README

Why

The existing workflow tries to preserve version directories by checking out a gh-pages branch, but this repository deploys Pages artifacts through GitHub Actions and does not maintain that branch. The result is extra workflow complexity without persistent version history. Publishing the requested latest-only documentation directly from Dokka's HTML output makes the deployment deterministic and keeps the site rooted at termlib.connectbot.org.

After merge, documentation deploys only from successful pushes to connectbot/termlib:main; tag pushes no longer publish separate documentation versions.

Validation

• ANDROID_HOME=/Users/haroldmartin/Library/Android/sdk ./gradlew :lib:dokkaGeneratePublicationHtml --no-configuration-cache
• ANDROID_HOME=/Users/haroldmartin/Library/Android/sdk ./gradlew spotlessCheck --no-configuration-cache
• parsed .github/workflows/ci.yml successfully
• verified the generated artifact contains the module overview, package list, search index, corrected GitHub source links, no internal implementation declarations, no symlinks, and no broken Markdown footer link
• smoke-tested the generated site locally for navigation, search, assets, source links, and browser console errors