Describe the bug

context
<title> tags for the docs could have a suffix that includes e.g. "| MyST-Parser Documentation" for searchability

expectation
I expected to: have more than "Overview" to visually identify and textually search for the myst-parser docs tab.

bug
But instead: it just says "Overview"

$ jupyter-book build mybook
ERROR ...

problem
This is a problem for people doing ___ because ___.

Reproduce the bug

• Visit: https://myst-parser.readthedocs.io/en/latest/ and view Title tag

List your environment

No response