docs: Add ADK Tools list to docs (#781)

* docs: Add ADK Tools list to docs

* docs: Update Plugins page (#780)

Add links to code examples, fix repetition of tips

* Update docs/tools/list.md

Co-authored-by: Kristopher Overholt <[email protected]>

* Update docs/tools/list.md

Co-authored-by: Kristopher Overholt <[email protected]>

* docs: Update Python API Reference to v1.16 release (#782)

* Update mkdocs.yml

* docs: reconfigure tools to emphasize pre-built tool

- added new tools listing page
- created separate directory for custom tool dev

* fix MCP Toolbox name

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Co-authored-by: Kristopher Overholt <[email protected]>
Co-authored-by: Kristopher Overholt <[email protected]>

Author: joefernandez