CircleCI CLI intsall link updated

What Changed?

The previous link to install CircleCI CLI tool was https://circleci.com/docs/2.0/local-cli/
I have changed this to https://circleci.com/docs/guides/toolkit/local-cli/

Why?

The previous link returned "Page Not Found"

Screenshots

Notes

[Any additional notes you'd like to add, including brief details of additional tests performed (or needed), or things TODO later on.]

Sanity Checklist

• I followed the naming conventions for the PR and branch; e.g. ENG-xxx: Title or NO-TICKET: Title.
• I considered security implications (if any) for the changes; e.g. permission checks on new endpoints.
• I have added a label that identifies the classification for this issue; e.g. "bug", "enhancement", "perf", etc.