Fix headings in docs (ClearML and Comet) (#2808)
This PR fixes the document structure in the
[Ecosystem](https://python.langchain.com/en/latest/ecosystem.html) page.
Also adds a fix for the heading on the
[Comet](https://python.langchain.com/en/latest/ecosystem/comet_tracking.html)
page for more consistency with other ecosystem tools.
## Screenshot
<img width="878" alt="image"
src="https://user-images.githubusercontent.com/6207830/231674921-9bf25376-cf14-4dba-be3c-08e0abda6154.png">
<img width="869" alt="image"
src="https://user-images.githubusercontent.com/6207830/231675105-d8e42df4-2d01-435b-9e09-3371522fd2ce.png">
