* docs: home page
* updates based on feedback
* respond to review feedback
* docs: update gemini selector strings to "flash-latest"
* Update homepage.css
* Replace google.github.io/adk-docs URLs and /adk-docs/ paths with adk.dev
Migrate all hardcoded documentation references to use the new custom
domain. Update root-relative links to remove the /adk-docs/ subpath
prefix since the site will be served from the root of adk.dev.
* Additional fixes
* docs: add language support tags to pages
- replace img.shield tags
- add language support tags where missing
* update Agents page with general tags
* update language and version tagging
- response to review comments
- rename css styles to avoid style name conflicts
* add tags to api-server page