docs: add GitKraken to third-party mcp server list (modelcontextprotocol#2528)

Co-authored-by: Chris Griffing <cmgriffing-at-gitkraken@users.noreply.github.com>

Author: cmgriffing-at-gitkraken

README.md

@@ -187,6 +187,7 @@ Official integrations are maintained by companies building production ready MCP
 - <img height="12" width="12" src="https://gitee.com/favicon.ico" alt="Gitee Logo" /> **[Gitee](https://github.com/oschina/mcp-gitee)** - Gitee API integration, repository, issue, and pull request management, and more.
 - <img height="12" width="12" src="https://cdn.prod.website-files.com/5ee25cbe47310017adf964da/6323888a9b9f4e22a7bc766b_GG%20Favicon.svg" alt="GitGuardian Logo" /> **[GitGuardian](https://github.com/GitGuardian/gg-mcp)** - GitGuardian official MCP server - Scan projects using GitGuardian's industry-leading API, which features over 500 secret detectors to prevent credential leaks before they reach public repositories. Resolve security incidents directly with rich contextual data for rapid, automated remediation.
 - <img height="12" width="12" src="https://github.githubassets.com/assets/GitHub-Mark-ea2971cee799.png" alt="GitHub Logo" /> **[GitHub](https://github.com/github/github-mcp-server)** - GitHub's official MCP Server.
+- <img height="12" width="12" src="https://www.gitkraken.com/wp-content/uploads/2021/03/android-chrome-144x144-1.png" alt="GitKraken Logo" /> **[GitKraken](https://github.com/gitkraken/gk-cli?tab=readme-ov-file#mcp-server)** - A CLI for interacting with GitKraken APIs. Includes an MCP server via `gk mcp` that not only wraps GitKraken APIs, but also Jira, GitHub, GitLab, and more.
 - <img height="12" width="12" src="https://app.glean.com/images/favicon3-196x196.png" alt="Glean Logo" /> **[Glean](https://github.com/gleanwork/mcp-server)** - Enterprise search and chat using Glean's API.
 - <img height="12" width="12" src="https://cdn.jsdelivr.net/gh/jsdelivr/globalping-media@refs/heads/master/icons/android-chrome-192x192.png" alt="Globalping Logo" /> **[Globalping](https://github.com/jsdelivr/globalping-mcp-server)** - Access a network of thousands of probes to run network commands like ping, traceroute, mtr, http and DNS resolve.
 - <img height="12" width="12" src="https://gnucleus.ai/favicon.ico" alt="gNucleus Logo" /> **[gNucleus Text-To-CAD](https://github.com/gNucleus/text-to-cad-mcp)** - Generate CAD parts and assemblies from text using gNucleus AI models.