docs: remove "CML" from titles

[jorgeorpinel]

Because | CML · Continuous Machine Learning is already auto-suffixed to all pages

• /doc = Documentation
• /doc/start/github = Get Started on GitHub
• /usage = Usage
• etc.

_Originally posted by @casperdcl in https://github.com/iterative/cml.dev/pull/382#discussion_r1031865273_

[jorgeorpinel]

... already auto-suffixed to all pages

Just keep in mind that in terms of SEO, Google sometimes decides to make up it's own page title e.g.

When they're repetitive, I guess?