Improve danger bot layout for telemetry review

Closes #217719 (closed)

What does this MR do?

Improve layout in danger bot warning for telemetry review

Improvements:

• added link to telemetry guide not sure though if is the best idea to link to wiki page but at least is some information
• added telemetry label some purple color to be more visible
• moved changed file list in warning, so now everything is in one place

cc @jeromezng @sid_reddy

Danger view screenshot after changes

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team