Add installation/source information for `mcp-cli` in SKILL.md

[nblog]

Problem

When using the skill described in skills/mcp-cli/SKILL.md there is no clear indication of where the mcp-cli command comes from. On my computer, the command mcp-cli does not exist by default, and the documentation does not specify how to obtain or install it.

Suggested Improvement

Please provide a clear and standardized source or installation method for the mcp-cli command in SKILL.md. For example, similar to the approach used in @clawdbot/clawdbot/files/skills/mcporter/SKILL.md , which includes metadata or a homepage link to guide users.

The absence of such information makes SKILL.md difficult to use, as users cannot find or install mcp-cli just from the current documentation.

[aaronpowell]

@AungMyoKyaw as you contributed this skill, can you improve it per the suggestion