Add Durable Agents documentation (#755)

* Add Durable Agents section and features documentation

* Fix build issues

* Refactor Durable Agents documentation to enhance key features section and improve clarity

* Add tutorial for creating and running a durable agent

* Add next steps and tutorial links to Durable Agents documentation

* Clarify Durable Extension references in tutorials and features documentation

* Enhance documentation for Durable Agents: clarify local development dependencies, improve explanations of state management features, and detail automatic checkpointing in tool calls.

* Fix tutorial links in Durable Agents documentation for correct navigation

* Update example messages in durable agent tutorial to address policheck errors

* Add diagrams

* Update filenames

* Update package installation instructions and import statements in Durable Agent tutorials

* Minor tweaks

* Update references from "Durable Extension" to "durable task extension" in tutorials and features documentation

* Update .NET examples based on the latest in official samples

* Update python samples

* Add durable agent orchestration tutorial

* Enhance durable agent tutorials with detailed endpoint descriptions and orchestration flow diagram

* Fix duplicate heading

* Refactor orchestration tutorial by removing mermaid diagram and updating step numbering for clarity

* Fix zone pivot

* Clean things up a bit

* Update user guides

* Update prerequisites and clarify deployment instructions for durable agents

* Add note on Microsoft.Azure.Functions.Worker package version requirement

* Enhance tutorial for creating durable agents: add virtual environment setup, update package installation instructions, and clarify usage of local.settings.json

* Update tutorial for durable agents: modify HTTP request examples to use text/plain content type and clarify thread ID usage

* Refine orchestration tutorial: clarify agent registration process and update translation agent description

* Fix link formatting in durable agent tutorial introduction

* Update durable agent examples to use DefaultAzureCredential instead of AzureCliCredential

* Update durable agent tutorial: replace example thread ID with a new value for consistency

* Remove long-running operations

* Update durable agent tutorial: standardize thread ID header and API endpoint usage based on microsoft/agent-framework#2118

* Update durable agent tutorials to use app.get_agent for agent retrieval based on microsoft/agent-framework#2141

* Update durable agent examples to use new thread ID format for consistency

* Ensure correct versions of worker sdk is installed

* Update tutorial to clarify modification of function_app.py content

* Update durable agent tutorial to use azd

* Update tutorial to clarify local.settings.json setup and remove redundant sections

* Update tutorial to clarify Durable Task Scheduler instance retrieval and monitoring steps

* Update tutorial to streamline prerequisites, clarify local development setup, and add deployment instructions for Azure

* Update tutorial to include null input handling in orchestration workflow and add curl examples for both C# and Python

* Update durable agent orchestration examples to include structured response handling and improve task management

* Edit pass on first tutorial

* Edit pass on second tutorial

* Apply suggestions from code review

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Address PR feedback

* Fix duplicate mention of Durable Task Scheduler instance in tutorial

* Apply PR suggestions

* Update agent-framework/tutorials/agents/orchestrate-durable-agents.md

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Update template references in durable agent tutorial

* Add PowerShell commands

* Refactor TOC.yml to group durable agent topics under a single section

* Update agent-framework/user-guide/agents/agent-types/durable-agent/features.md

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Update agent-framework/user-guide/agents/agent-types/durable-agent/features.md

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Update agent-framework/user-guide/agents/agent-types/durable-agent/features.md

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Update agent-framework/user-guide/agents/agent-types/durable-agent/features.md

Co-authored-by: Chris Gillum <cgillum@gmail.com>

* Address feedback suggestions

---------

Co-authored-by: Chris Gillum <cgillum@gmail.com>

Author: anthonychu

agent-framework/media/durable-agent-chat-history-tutorial.png

@@ -23,4 +23,10 @@
 - name: Third Party chat history storage
   href: third-party-chat-history-storage.md
 - name: Adding memory to agents
-  href: memory.md
+  href: memory.md
+- name: Durable agents
+  items:
+  - name: Create and run a durable agent
+    href: create-and-run-durable-agent.md
+  - name: Orchestrate durable agents
+    href: orchestrate-durable-agents.md