Add MCPBundle Studio (For clients) and MCP Bundles Hub (Resources)

[TonyLLondon]

Two single-line additions to README.md.

What

• ### For clients — adds MCPBundle Studio, a browser-based MCP client for inspecting tool schemas, executing tools (form-based or chat input), and rendering interactive Apps returned by tool responses. Supports OAuth and API-key auth over streamable HTTP. https://www.mcpbundles.com/studio
• ## 📚 Resources — adds MCP Bundles Hub, a hosted directory of 650+ custom-built and 800+ third-party hosted MCP servers. Provides workspace-scoped credential management, OAuth/API-key brokerage, and a unified streamable HTTP endpoint so an agent can connect to many providers through one bundle. https://mcpbundles.com

Why

Both projects are actively used by developers in the MCP ecosystem and fit the existing scope of these two sections (Studio is a client; Hub is a directory/resource).

Notes

• Diff is exactly two lines added, no other changes.
• Both entries follow the formatting and tone of surrounding entries in their sections.
• Hub counts (650+ / 800+) are conservative round-downs of live values to stay accurate as the directory grows.

[TonyLLondon]

/i-promise-this-is-not-a-new-server

Confirming for the maintainer bot: this PR does not add anything to the retired Community Servers / third-party server list. It adds two entries to sections that are still actively maintained:

1. ### For clients — adds MCPBundle Studio, a browser-based MCP client.
2. ## 📚 Resources — adds MCP Bundles Hub, a hosted MCP server directory.

Diff is +2 / −0 in README.md (no other changes). Happy to adjust wording, ordering, or split this into two PRs if preferred.

(Note: the failing check-readme-only job appears to be hitting a 403 when trying to apply the `readme: pending` label — looks like the workflow's GITHUB_TOKEN is missing `issues: write` on cross-fork PRs. That's unrelated to the PR contents.)

[cliffhall]

"Request to add server to README" section of @upstream-prs-triage.md with the message "Thanks for your interest in contributing! We are no longer accepting PRs to add server or framework listings to this README. Please publish your server to the MCP Server Registry instead — you can follow the quickstart guide to get listed."