add GitHub integration page (#329)

* add GitHub integration page

* add github logo

* remove unused imports

* Apply suggestions from code review

Co-authored-by: Bilge Yücel <bilge.yucel@deepset.ai>

* type: Tool Integration

* move repo_viewer_tool in example code

---------

Co-authored-by: Bilge Yücel <bilge.yucel@deepset.ai>

Author: julian-risch

integrations/github.md

@@ -0,0 +1,127 @@
+---
+layout: integration
+name: github
+description: Interact with GitHub repositories, issues, and pull requests within Haystack
+authors:
+    - name: deepset
+      socials:
+        github: deepset-ai
+        twitter: deepset_ai
+        linkedin: https://www.linkedin.com/company/deepset-ai/
+pypi: https://pypi.org/project/github-haystack
+repo: https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/github
+type: Tool Integration
+report_issue: https://github.com/deepset-ai/haystack-core-integrations/issues
+logo: /logos/github.png
+version: Haystack 2.0
+toc: true
+---
+
+### **Table of Contents**
+
+- [Overview](#overview)
+- [Installation](#installation)
+- [Usage](#usage)
+
+## Overview
+
+The GitHub integration for Haystack provides a set of components and tools to interact with GitHub repositories, issues, and pull requests. It enables you to view repository contents, manage issues, create pull requests, and more within your Haystack agents and pipelines.
+
+
+Some of the components and tools in this integration require GitHub authentication with a personal access token. 
+For example, authentication is required to post a comment on GitHub, fork a repository, or open a pull request. You can create a (fine-graind personal access token)[https://github.com/settings/personal-access-tokens] or a [classic personal access token](https://github.com/settings/tokens) on GitHub and then expose it via an environment variable called `GITHUB_API_KEY`.
+
+
+## Installation
+
+Install the GitHub integration with pip:
+
+```bash
+pip install github-haystack
+```
+
+## Usage
+
+This integration comes with several components and tools:
+
+### Components
+- `GitHubIssueViewer`: View issues and their details
+- `GitHubIssueCommenter`: Add comments to issues
+- `GitHubRepoViewer`: View repository contents and metadata
+- `GitHubRepoForker`: Fork repositories
+- `GitHubFileEditor`: Edit files in repositories
+- `GitHubPRCreator`: Create pull requests
+
+### Tools
+- `GitHubIssueViewerTool`: View issues
+- `GitHubIssueCommenterTool`: Comment on issues
+- `GitHubRepoViewerTool`: View repository contents
+- `GitHubFileEditorTool`: Edit repository files
+- `GitHubPRCreatorTool`: Create pull requests
+
+### Example Usage
+
+```python
+from typing import List
+
+from haystack import Pipeline
+from haystack.components.agents import Agent
+from haystack.components.builders import ChatPromptBuilder
+from haystack.dataclasses import ChatMessage, Document
+from haystack.tools.from_function import tool
+
+from haystack_integrations.components.connectors.github import GitHubIssueViewer
+from haystack_integrations.components.generators.anthropic import AnthropicChatGenerator
+from haystack_integrations.prompts.github import SYSTEM_PROMPT
+from haystack_integrations.tools.github import GitHubRepoViewerTool
+
+@tool
+def create_comment(comment: str) -> str:
+    """
+    Use this to create a Github comment once you finished your exploration.
+    """
+    # A mockup tool to showcase how Agent uses tools. You should use `GitHubIssueCommenterTool` instead of this one to write comments on GitHub.
+    return comment
+
+repo_viewer_tool = GitHubRepoViewerTool()
+
+chat_generator = AnthropicChatGenerator(model="claude-3-5-sonnet-latest", generation_kwargs={"max_tokens": 8000})
+
+agent = Agent(
+    chat_generator=chat_generator,
+    system_prompt=SYSTEM_PROMPT,
+    tools=[repo_viewer_tool, create_comment],
+    exit_conditions=["create_comment"],
+    state_schema={"documents": {"type": List[Document]}},
+)
+
+issue_template = """
+Issue from: {{ url }}
+{% for document in documents %}
+{% if loop.index == 1 %}
+**Title: {{ document.meta.title }}**
+{% endif %}
+<issue-comment>
+{{document.content}}
+</issue-comment>
+{% endfor %}
+"""
+
+issue_builder = ChatPromptBuilder(template=[ChatMessage.from_user(issue_template)], required_variables="*")
+
+issue_fetcher = GitHubIssueViewer()
+
+pipeline = Pipeline()
+
+pipeline.add_component("issue_fetcher", issue_fetcher)
+pipeline.add_component("issue_builder", issue_builder)
+pipeline.add_component("agent", agent)
+
+pipeline.connect("issue_fetcher.documents", "issue_builder.documents")
+pipeline.connect("issue_builder.prompt", "agent.messages")
+
+issue_url = "https://github.com/<owner>/<repo>/issues/1268"
+
+result = pipeline.run({"url": issue_url})
+print(result["agent"]["last_message"].tool_call_result.result)
+```