build(docs)🗑️: remove documentation and related build files for mkdocs

- Delete the docs/ directory and all documentation files including markdown, CSS, and JS assets.
- Remove mkdocs.yaml configuration file.
- Remove MANIFEST.in as it is no longer needed for documentation assets.
- Update pyproject.toml to explicitly include puns.json as package data for scipyconference.
- Update pixi.lock to reflect changes in package data and hash.

Author: ericmjl

MANIFEST.in

@@ -60,6 +60,9 @@ select = ["E", "F", "I"]
 [tool.setuptools]
 include-package-data = true
 
+[tool.setuptools.package-data]
+scipyconference = ["puns.json"]
+
 [tool.setuptools.packages.find]
 where = ["."]
 namespaces = false