Remove redundant param for get_me and update contribution guide

[tonytrg]

This pr:

• removes the reason argument for get_me tool call.
• adds a bit of information to the contribution guide.
• prompt changes
  • encourage the llm to use this command in a chain if additional information is needed
  • it is unnecesary to tell the llm to not call a tool again which it still has the tool response cached in the session

[Copilot]

Pull Request Overview

This PR removes the now-unnecessary reason parameter from the get_me tool and updates related documentation and snapshots.

• Removed the reason field from the Go tool definition and its snapshot
• Updated README to indicate no parameters are required
• Reformatted the CONTRIBUTING guide’s checklist for clarity

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
pkg/github/context_tools.go	Removed mcp.WithString("reason",…) calls in GetMe
pkg/github/toolsnaps/get_me.snap	Cleared out the reason property in the snapshot
README.md	Changed parameter list to “No parameters required”
CONTRIBUTING.md	Converted hyphenated list to numbered steps and added detail

Comments suppressed due to low confidence (2)

README.md:553

• [nitpick] Indent the "No parameters required" bullet under the get_me entry so it correctly nests as a sub-item in the markdown list.

  - No parameters required

CONTRIBUTING.md:27

• [nitpick] Indent these hyphenated sub-steps under step 5 to ensure they render as nested list items in the markdown.

- Run linter: `script/lint`

[LuluBeatson]

nit: indent these so they appear as nested inside step 5