docs: Overhaul AI documentation (#29747)

To support the Agentic Editing launch. To dos before merging:

- [ ] Anything marked as `todo!` within `docs/src` (Anyone)
- [x] Check all internal links (Joe)
- Joe: I checked all links and fixed all aside from a few that I
annotated with `todo!` comments
- [ ] Update images (Danilo)
- [ ] Go over / show images of tool cards in agent panel overview
(Danilo)
- [ ] Point billing FAQ to new billing docs (Joe)
- [x] Redirects external links
    - [ ] Needs testing
- [x] Delete old docs
- [ ] Ensure all mentioned bindings use the `{#kb ...}` format and that
they are rendering correctly
- [ ] All agent-related actions are now `agent::` and not `assistant::`
- [x] Mention support of `.rules` files in `rules.md`

Release Notes:

- N/A

---------

Co-authored-by: Joseph T. Lyons <josephtlyons@gmail.com>
Co-authored-by: morgankrey <morgankrey@gmail.com>
Co-authored-by: Smit Barmase <37347831+smitbarmase@users.noreply.github.com>
Co-authored-by: Ben Kunkle <Ben.kunkle@gmail.com>
Co-authored-by: Peter Tripp <peter@zed.dev>
Co-authored-by: Ben Kunkle <ben@zed.dev>
Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

docs/src/ai/ai.md

@@ -0,0 +1,35 @@
+# AI
+
+Zed offers various features that integrate LLMs smoothly into the editor.
+
+## Setting up AI in Zed
+
+- [Models](./models.md): Information about the various language models available in Zed.
+
+- [Configuration](./configuration.md): Configure the Agent, and set up different language model providers like Anthropic, OpenAI, Ollama, Google AI, and more.
+
+- [Custom API Keys](./custom-api-keys.md): How to use your own API keys with the AI features.
+
+- [Subscription](./subscription.md): Information about Zed's subscriptions and other billing related information.
+
+- [Privacy and Security](./privacy-and-security.md): Understand how Zed handles privacy and security with AI features.
+
+## Agentic Editing
+
+- [Agent Panel](./agent-panel.md): Create and collaboratively edit new threads, and manage interactions with language models.
+
+- [Rules](./rules.md): How to define rules for AI interactions.
+
+- [Tools](./tools.md): Explore the tools that enhance the AI's capabilities to interact with your codebase.
+
+- [Model Context Protocol](./mcp.md): Learn about context servers that enhance the Assistant's capabilities.
+
+- [Inline Assistant](./inline-assistant.md): Discover how to use the agent to power inline transformations directly within your code editor and terminal.
+
+## Edit Prediction
+
+- [Edit Prediction](./edit-prediction.md): Learn about Zed's Edit Prediction feature that helps autocomplete your code.
+
+## Text Thread Interface
+
+- [Text Threads](./text-threads.md): Learn about an alternative text-based interface for interacting with language models.