Rename 'linkml' dir name to `schema` and relocate it.

[hrshdhgd]

This request is with regards to what I came across as a solution that works when a project developed through linkml-ws is released to pypi.

The directory structure should be like this:

📦src
 ┣ 📂data
 ┃ ┗ 📂examples
 ┃ ┃ ┗ 📜Person-001.yaml
 ┣ 📂docs
 ┃ ┗ 📜about.md
 ┣ 📂project-name
 ┃ ┣ 📂datamodel
 ┃ ┃ ┗ 📜 project-name.py
 ┃ ┗ 📂schema [**previously linkml**]
 ┃ ┃ ┣ 📜basics.yaml
 ┃ ┃ ┣ 📜project-name.yaml
 ┃ ┃ ┣ 📜ontology_model.yaml
 ┃ ┃ ┗ 📜some_other.yaml

So the suggestion is rename the 'linkml' directory to 'schema' and move it under the src/project-name directory. On releasing to PyPi, this structure is easily recognized and there does not need to be any include or packages in the pyproject.toml.

[sujaypatil96]

Can we add also add a sub folder called doc-templates or simply templates under the src folder to include the jinja2 templates that gen-doc uses?

CC: @hrshdhgd